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
(Libretro) Add frame duping core option

Conflicts:
	frontend/libretro.c
libretro: (OSX) Set min OS version to 10.6
libretro: align vout_buf to 128-bit
libretro: only use posix_memalign when it's safe
libretro: Add OSX version minor detection to Makefile

Conflicts:
	Makefile.libretro
libretro: Set performance level
libretro: Makefile - fixup Windows build
libretro: adjust indentation style

The indentation style should be at least consistent
inside a single function.
libretro: Update libretro.h
libretro: Update Makefile

Conflicts:
	Makefile.libretro
libretro: Implement input descriptors
libretro: Update input descriptors
libretro: Add core options to namespace

Conflicts:
	frontend/libretro.c
frontend: update libpicofe
psxinterpreter: don't break strict aliasing rules
spu: fix some fmod related breakage
spu: add a schedule callback