Update libjpeg_turbo to 1.4.90 from https://github.com/libjpeg-turbo/

README.ijg

 libjpeg-turbo note:  This file has been modified by The libjpeg-turbo Project
 to include only information relevant to libjpeg-turbo, to wordsmith certain
 sections, and to remove impolitic language that existed in the libjpeg v8
-README.  It is included only for reference.  Please see README-turbo.txt for
+README.  It is included only for reference.  Please see README.md for
 information specific to libjpeg-turbo.
 
 
 The Independent JPEG Group's JPEG software
 ==========================================
 
 This distribution contains a release of the Independent JPEG Group's free JPEG
 software.  You are welcome to redistribute this software and to use it for any
 purpose, subject to the conditions under LEGAL ISSUES, below.
 
@@ skipping 14 matching lines @@
 OVERVIEW            General description of JPEG and the IJG software.
 LEGAL ISSUES        Copyright, lack of warranty, terms of distribution.
 REFERENCES          Where to learn more about JPEG.
 ARCHIVE LOCATIONS   Where to find newer versions of this software.
 FILE FORMAT WARS    Software *not* to get.
 TO DO               Plans for future IJG releases.
 
 Other documentation files in the distribution are:
 
 User documentation:
-  install.txt       How to configure and install the IJG software.
   usage.txt         Usage instructions for cjpeg, djpeg, jpegtran,
                     rdjpgcom, and wrjpgcom.
   *.1               Unix-style man pages for programs (same info as usage.txt).
   wizard.txt        Advanced usage instructions for JPEG wizards only.
   change.log        Version-to-version change highlights.
 Programmer and internal documentation:
   libjpeg.txt       How to use the JPEG library in your own programs.
   example.c         Sample code for calling the JPEG library.
   structure.txt     Overview of the JPEG library's internal structure.
   coderules.txt     Coding style rules --- please read if you contribute code.
 
-Please read at least the files install.txt and usage.txt.  Some information
-can also be found in the JPEG FAQ (Frequently Asked Questions) article.  See
-ARCHIVE LOCATIONS below to find out where to obtain the FAQ article.
+Please read at least usage.txt.  Some information can also be found in the JPEG
+FAQ (Frequently Asked Questions) article.  See ARCHIVE LOCATIONS below to find
+out where to obtain the FAQ article.
 
 If you want to understand how the JPEG code works, we suggest reading one or
 more of the REFERENCES, then looking at the documentation files (in roughly
 the order listed) before diving into the code.
 
 
 OVERVIEW
 ========
 
 This package contains C software to implement JPEG image encoding, decoding,
 and transcoding.  JPEG (pronounced "jay-peg") is a standardized compression
-method for full-color and gray-scale images.  JPEG's strong suit is compressing
+method for full-color and grayscale images.  JPEG's strong suit is compressing
 photographic images or other types of images that have smooth color and
 brightness transitions between neighboring pixels.  Images with sharp lines or
 other abrupt features may not compress well with JPEG, and a higher JPEG
 quality may have to be used to avoid visible compression artifacts with such
 images.
 
 JPEG is lossy, meaning that the output pixels are not necessarily identical to
 the input pixels.  However, on photographic content and other "smooth" images,
 very good compression ratios can be obtained with no visible compression
 artifacts, and extremely high compression ratios are possible if you are
@@ skipping 46 matching lines @@
    program, you must acknowledge somewhere in your documentation that
    you've used the IJG code.
 
 In legalese:
 
 The authors make NO WARRANTY or representation, either express or implied,
 with respect to this software, its quality, accuracy, merchantability, or
 fitness for a particular purpose.  This software is provided "AS IS", and you,
 its user, assume the entire risk as to its quality and accuracy.
 
-This software is copyright (C) 1991-2012, Thomas G. Lane, Guido Vollbeding.
+This software is copyright (C) 1991-2016, Thomas G. Lane, Guido Vollbeding.
 All Rights Reserved except as specified below.
 
 Permission is hereby granted to use, copy, modify, and distribute this
 software (or portions thereof) for any purpose, without fee, subject to these
 conditions:
 (1) If any part of the source code for this software is distributed, then this
 README file must be included, with this copyright and no-warranty notice
 unaltered; and any additions, deletions, or changes to the original files
 must be clearly indicated in accompanying documentation.
 (2) If only executable code is distributed, then the accompanying
@@ skipping 17 matching lines @@
 assumed by the product vendor.
 
 
 The Unix configuration script "configure" was produced with GNU Autoconf.
 It is copyright by the Free Software Foundation but is freely distributable.
 The same holds for its supporting scripts (config.guess, config.sub,
 ltmain.sh).  Another support script, install-sh, is copyright by X Consortium
 but is also freely distributable.
 
 The IJG distribution formerly included code to read and write GIF files.
-To avoid entanglement with the Unisys LZW patent, GIF reading support has
-been removed altogether, and the GIF writer has been simplified to produce
-"uncompressed GIFs".  This technique does not use the LZW algorithm; the
-resulting GIF files are larger than usual, but are readable by all standard
-GIF decoders.
+To avoid entanglement with the Unisys LZW patent (now expired), GIF reading
+support has been removed altogether, and the GIF writer has been simplified
+to produce "uncompressed GIFs".  This technique does not use the LZW
+algorithm; the resulting GIF files are larger than usual, but are readable
+by all standard GIF decoders.
 
 We are required to state that
     "The Graphics Interchange Format(c) is the Copyright property of
     CompuServe Incorporated.  GIF(sm) is a Service Mark property of
     CompuServe Incorporated."
 
 
 REFERENCES
 ==========
 
 We recommend reading one or more of these references before trying to
 understand the innards of the JPEG software.
 
 The best short technical introduction to the JPEG compression algorithm is
         Wallace, Gregory K.  "The JPEG Still Picture Compression Standard",
         Communications of the ACM, April 1991 (vol. 34 no. 4), pp. 30-44.
 (Adjacent articles in that issue discuss MPEG motion picture compression,
 applications of JPEG, and related topics.)  If you don't have the CACM issue
-handy, a PostScript file containing a revised version of Wallace's article is
-available at http://www.ijg.org/files/wallace.ps.gz.  The file (actually
+handy, a PDF file containing a revised version of Wallace's article is
+available at http://www.ijg.org/files/Wallace.JPEG.pdf.  The file (actually
 a preprint for an article that appeared in IEEE Trans. Consumer Electronics)
 omits the sample images that appeared in CACM, but it includes corrections
 and some added material.  Note: the Wallace article is copyright ACM and IEEE,
 and it may not be used for commercial purposes.
 
 A somewhat less technical, more leisurely introduction to JPEG can be found in
 "The Data Compression Book" by Mark Nelson and Jean-loup Gailly, published by
 M&T Books (New York), 2nd ed. 1996, ISBN 1-55851-434-1.  This book provides
 good explanations and example C code for a multitude of compression methods
 including JPEG.  It is an excellent source if you are comfortable reading C
@@ skipping 35 matching lines @@
 of the TIFF spec will replace the 6.0 JPEG design with the Note's design.
 Although IJG's own code does not support TIFF/JPEG, the free libtiff library
 uses our library to implement TIFF/JPEG per the Note.
 
 
 ARCHIVE LOCATIONS
 =================
 
 The "official" archive site for this software is www.ijg.org.
 The most recent released version can always be found there in
-directory "files".  This particular version will be archived as
-http://www.ijg.org/files/jpegsrc.v8d.tar.gz, and in Windows-compatible
-"zip" archive format as http://www.ijg.org/files/jpegsr8d.zip.
+directory "files".
 
 The JPEG FAQ (Frequently Asked Questions) article is a source of some
 general information about JPEG.
 It is available on the World Wide Web at http://www.faqs.org/faqs/jpeg-faq/
 and other news.answers archive sites, including the official news.answers
 archive at rtfm.mit.edu: ftp://rtfm.mit.edu/pub/usenet/news.answers/jpeg-faq/.
 If you don't have Web or FTP access, send e-mail to mail-server@rtfm.mit.edu
 with body
         send usenet/news.answers/jpeg-faq/part1
         send usenet/news.answers/jpeg-faq/part2
@@ skipping 10 matching lines @@
 common, interoperable format standards for JPEG files.
 Don't use an incompatible file format!
 (In any case, our decoder will remain capable of reading existing JPEG
 image files indefinitely.)
 
 
 TO DO
 =====
 
 Please send bug reports, offers of help, etc. to jpeg-info@jpegclub.org.