Fix HostSys::Munmap function declaration.

It's arguments are defined to be (void*, size_t) but with the function declaration they were (void*, u32).
Wipe the clusterfsck that was the get16bits define in HashTools.

This define takes a pointer(s8* in this case) and grabs 16bits of data from the array it points to.
This can be done the generic way on all compilers, no need for specifying it another way.
Fix SpatialArrayReserve::SetBlockSize function declaration to match definition.
The function was defined to use uptr, but the declaration was using uint.
Merge pull request #98 from Sonicadvance1/minor_cleanup

Some minor cleanups to the codebase.