Lightweight Java Game Library Code

Windows: LWJGL didn't work well with jinput, but compatibility could be greatly improved if LWJGL used DirectInput 8 (like jinput). This can't be done unconditionally, since we need the DX3 support for older versions of windows. So, I've moved most Mouse and Keyboard stuff from native to java side and generalized DirectInput access through an abstract base class, with two concrete subclasses, one for dx3 and one for dx8.

Converted win32 specific native source from C++->C (removes the strange debug flag behaviour exhibited by SourceLimitTest.java)