Fix preprocessor/compiler warning due to unbalanced apostophe (') character

Reworded the warning message to be displayed when the fall-through case is taken by the preprocessor in `mono_thread_get_stack_bounds()`.
Merge pull request #695 from jack-pappas/patch-4

Fix preprocessor/compiler warning due to unbalanced apostophe (') character
configure: Set TARGET=S390X instead of S390x for consistency.
Add atomic.c/.h to libmonoutils.vcxproj.
Ignore only local Makefile
Add libmonoboehm package to the spec file.
[PCL]: Add System.Linq.Expressions type-forwarders.
Oops, remove extra %endif in .spec file.