third_party/protobuf: Update to HEAD (83d681ee2c)

third_party/protobuf/configure.ac

 ## Process this file with autoconf to produce configure.
 ## In general, the safest way to proceed is to run ./autogen.sh
 
 AC_PREREQ(2.59)
 
 # Note:  If you change the version, you must also update it in:
-# * java/pom.xml
-# * python/setup.py
+# * Protobuf.podspec
+# * csharp/Google.Protobuf.Tools.nuspec
+# * csharp/src/*/AssemblyInfo.cs
+# * csharp/src/Google.Protobuf/Google.Protobuf.nuspec
+# * java/*/pom.xml
+# * python/google/protobuf/__init__.py
+# * protoc-artifacts/pom.xml
 # * src/google/protobuf/stubs/common.h
 # * src/Makefile.am (Update -version-info for LDFLAGS if needed)
 #
 # In the SVN trunk, the version should always be the next anticipated release
 # version with the "-pre" suffix.  (We used to use "-SNAPSHOT" but this pushed
 # the size of one file name in the dist tarfile over the 99-char limit.)
-AC_INIT([Protocol Buffers],[3.0.0-beta-3],[protobuf@googlegroups.com],[protobuf])
+AC_INIT([Protocol Buffers],[3.1.0],[protobuf@googlegroups.com],[protobuf])
 
 AM_MAINTAINER_MODE([enable])
 
 AC_CONFIG_SRCDIR(src/google/protobuf/message.cc)
 # The config file is generated but not used by the source code, since we only
 # need very few of them, e.g. HAVE_PTHREAD and HAVE_ZLIB. Those macros are
 # passed down in CXXFLAGS manually in src/Makefile.am
 AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_MACRO_DIR([m4])
 
 AC_ARG_VAR(DIST_LANG, [language to include in the distribution package (i.e., make dist)])
 case "$DIST_LANG" in
   "") DIST_LANG=all ;;
-  all | cpp | csharp | java | python | javanano | objectivec | ruby | js) ;;
+  all | cpp | csharp | java | python | javanano | objectivec | ruby | js | php) ;;
   *) AC_MSG_FAILURE([unknown language: $DIST_LANG]) ;;
 esac
 AC_SUBST(DIST_LANG)
 
 # autoconf's default CXXFLAGS are usually "-g -O2".  These aren't necessarily
 # the best choice for libprotobuf.
 AS_IF([test "x${ac_cv_env_CFLAGS_set}" = "x"],
       [CFLAGS=""])
 AS_IF([test "x${ac_cv_env_CXXFLAGS_set}" = "x"],
       [CXXFLAGS=""])
@@ skipping 126 matching lines @@
 
 # Enable ObjC support for conformance directory on OS X.
 OBJC_CONFORMANCE_TEST=0
 case "$target_os" in
   darwin*)
     OBJC_CONFORMANCE_TEST=1
     ;;
 esac
 AM_CONDITIONAL([OBJC_CONFORMANCE_TEST], [test $OBJC_CONFORMANCE_TEST = 1])
 
+AX_CXX_COMPILE_STDCXX([11], [noext], [optional])
+
 # HACK:  Make gmock's configure script pick up our copy of CFLAGS and CXXFLAGS,
 #   since the flags added by ACX_CHECK_SUNCC must be used when compiling gmock
 #   too.
 export CFLAGS
 export CXXFLAGS
 AC_CONFIG_SUBDIRS([gmock])
 
 AC_CONFIG_FILES([Makefile src/Makefile benchmarks/Makefile conformance/Makefile protobuf.pc protobuf-lite.pc])
 AC_OUTPUT