Win32 Build fixes

- Force-redirects from 'config.h' to 'win32/config.h' if MSVC is
  detected. This allows them to be used in the same source tree
  without completely cleaning it
- CMake now outputs 'libcouchbase.dll' which is the name we use on
  windows (though 'couchbase.dll' is more correct)
- Pass /TC for compilation of C files. This speeds things up
- Pass /MP for compilation. This speeds things up

Fixes for using CMake with mingw cross compiler:

- Include "Real" stdint.h when using mingw
- Don't use MixedCase includes. This breaks on linux
- Don't re-define snprintf if mingw is used

Conform to VS build rules:
- Mixed declarations and code

Change-Id: Ie8fa2ff5b41623e148a4f007d9072d73a75fa09e