Moved the C99 support headers to windows-msvc

The C99 support headers do not need any library, and should work with
any version of MSVC, whereas the xdr and cairo headers are tied to a
particular version of some libraries that are paired with binary
prebuild libraries.

It should now be possible to build on any MSVC toolchain if all
dependencies are built correctly.
Merge pull request #22 from cryos/windows-inttypes

Moved the C99 support headers to windows-msvc