Support Windows builds with MinGW

- Our surrogate inttypes.h is only needed for Visual Studio 2010 and
  earlier, due to the lack of C99 support.
- Move all the inttypes.h includes into host_config.h, where we can
  do the ugly in a centralized location
- MinGW on Linux is case-sensitive -- reflect that when including
  windows.h.
update debian/copyright to match inttypes_msvc.h rename
Merge pull request #264 from rtucker/win-mingw-fixes-inttypes

Support Windows builds with MinGW