Update XZ Utils to 5.0.3 (in deps)

windows/INSTALL-Windows.txt

Index: windows/INSTALL-Windows.txt
===================================================================
--- windows/INSTALL-Windows.txt	(revision 50504)
+++ windows/INSTALL-Windows.txt	(working copy)
@@ -118,14 +118,23 @@
         cd /c/devel
         tar xzf xz-5.x.x.tar.gz
         cd xz-5.x.x
-        sh windows/build.sh
+        bash windows/build.bash
 
     If you used some other directory than C:\devel\tools for the build
-    tools, edit the variables near the beginning of build.sh first.
+    tools, edit the variables near the beginning of build.bash first.
 
     If you want to build manually, read the buildit() function in
-    build.sh. Look especially at the latter configure invocation.
+    build.bash. Look especially at the latter configure invocation.
 
     Be patient. Running configure and other scripts used by the build
     system is (very) slow under Windows.
 
+
+Using a snapshot from the Git repository
+
+    To use a snapshot, the build system files need to be generated with
+    autogen.sh or "autoreconf -fi" before trying to build using the
+    above build instructions. You can install the relevant extra packages
+    from MinGW or use Cygwin or use e.g. a GNU/Linux system to create a
+    source package with the required build system files.
+