1) Build fix
2) Implement input descriptors
Update input descriptors
Add core options to namespace
psxmem: remove hard requirement for a mapping

not all platforms have 1f800000 free
not all mmap implementations use the addr hint..
misc: don't succeed on trash input
misc: length is unsigned
Merge pull request #9 from Kekun/fix-load-invalid-game

Fixes an infinite loop when loading an invalid game
Add mman wrapper for Win32 and use it for PCSX ReARmed libretro Win32
Just use memmap.h header include in general
Cleanup Makefile.libretro.