Make the gc descriptor tests fail consistently if python is not found.
Fix monodis compilation on mingw which is missing some fp classification functions.
Fix mingw compilation problems.
Remove the usage of gcc-3 on mingw, the gcc-3 package no longer exists on cygwin. Mono can be built by configuring with --host=i686-pc-mingw32. Building without this will not work, since the libtool wrapper executables created by libtool will be unusable, i.e. they exit before the real runtime process exits.
Fix bug #8637 - omit xml declaration for ToString().
Fixed bug #4668 - C# compiler doesn't like decimal in custom attribute values, so use string.
Fix 5d37fac7c8765253a2ae406329ebf360c8429387 again.
Fixed bug #4141 - XmlSchemaImporter needs to consider attributeGroupRef in some case.
Update reference file
Add more implicit generic array interfaces. Fixes #8934
Fix bug #4344 - xsl:stylesheet always ignored xsl template contents.
Fix #13604 - STW handshake/thread shutdown race condition.
Fixed MSVC build, ported to Visual Studio 2012.
Improved exception handling with vectored exception handling.
Now a native debugger can be used with soft debugger running without triggering any exception. Code provided by Jonathan Chambers:

* https://github.com/Unity-Technologies/mono/commit/e9f9f7170914c5caaff3e95e09f6f58ecced2a10
* https://github.com/Unity-Technologies/mono/commit/4c2e1db60ccb38e792545d595d85b12ff309a919
* https://github.com/Unity-Technologies/mono/commit/bd7e534aa7da49b89787b8c1b40e165a34c0e960
* https://github.com/Unity-Technologies/mono/commit/b885251a83969d243deabc56bb3d1495d4a971dc
Fixed SGen build for MSVC
Working SGen on Windows/MSVC build.

NOTES:
 * All GC tests with exception on OOM handling passed.
 * mono_thread_state_init_from_handle signature changed as Windows can't access other thread native TLS.
Fixed incorrect pointer arithmetic on SGen for MSVC.