Allows static libraries and DLLs to be built without having
to do a 'make clean' in between on Cygwin and MinGW targets.
The Cygwin build still crashes when SHARED_LIBRARIES = YES
though, loading Com.dll seems to cause the problem.
Now works properly on Darwin where the version number comes
before the .dylib extension. This also makes Windows-specific
conditional tests fully generic.
Tom Pelaia II and Mark Engbretson contributed the build configuration
and OS-dependent files, I modified the build config to bring it up to
R3.14.12 standards and added the Release Notes.