Fixup manifest.

Crashed with full org.retroarch. path.
Initial support for nVidia Shield.
Fix X/Y on Shield.
Reword XML shaders to GLSL shaders.
Fix Shield analogs.
(Shield) Bind proper Start button
Use data dir and not cache dir.

Cache dir is volatile and can be cleaned out by OS at any minute.
(Shield) Bind R3 button
(Shield) Bind Start button to RGUI toggle
(Android/Shield) Add optimal settings option
(Android/Shield) Improve device detection/autoconfiguration - refresh rate still not
set correctly I think
Merge git://github.com/libretro/RetroArch

Conflicts:
	android/native/jni/input_android.c
Completely new approach for threaded video.

Allows a good compromise between jitter and avoiding audio stutter.