git has me really confused right now, first requiring a merge, then
not needing any merge. Anyway, add pull request #624 which was
unintentinoally closed and then couldn't re-opened. Now it's been
incorporated so is intentionally closed.
Closes #624
mingw32 build updates and replacement of sys/windows/Makefile.gcc with new
sys/windows/Makefile.mingw32 and sys/windows/Makefile.mingw32.depend
(pr #661 by feiyunw)
+mark various pointers to const char as const pointers (pr #624 by argrath)
Code Cleanup and Reorganization