Those are a few trivial fixes:

- Fixed includes on case sensitive OSes (also renamed constants.h to
Constatns.h, which was used in more places)
- Use __GXX_RTTI instead of assuming that all non-MSVC compilers support rtti
(fixes compilation in Mozilla tree, where -fno-rtti is used)
- Specify hashing of DXGI_FORMAT because this enum has no hash<> specialization

Signed-off-by: Shannon Woods
Author: cjacek@gmail.com