Add preliminary disk swapping interface.

Works with Mednafen's disk swapping model.
Merge branch 'master' into cd-swap
Merge branch 'master' into cd-swap
Log which SwapInterval implementation is used.
start of RGUI port to Android

currently detects menu button to bring up RGUI, but GL does not draw it
yet and you cannot exit from the (invisible) RGUI menu yet
commit makefile changes
change some logs around

detect menu key from any "controller"
Set texture filtering for RGUI texture.
get touch navigation working

fix colors for GL
make seperate option list for non-consoles
allow orientation changes in RGUI

allow closing RGUI menu, need to make the key binds sane
Merge branch 'android-rgui' of https://github.com/Themaister/RetroArch into android-rgui

Conflicts:
	android/native/jni/input_android.c
Brings up RMenu now for me
(GX) compile fix
Combine rmenu_generic.c and rmenu_gx.c
Merge branch 'master' of https://github.com/Themaister/RetroArch into android-rgui
(Android) Hook up PS Button to RGUI toggle
(Android) Hook up AKEYCODE_MENU to RGUI toggle
don't pop menu stack if it's the last one
Move FBO enums to gl_common.h
Merge branch 'android-rgui' of https://github.com/Themaister/RetroArch into android-rgui