Fix libretro GL state bug on frame dupe.

Need to force backbuffer and viewport on duped frames.
Small cleanup.
add 360 guide button->menu_toggle autoconf
Merge pull request #301 from pinumbernumber/xinput-guideauto

360 autoconf: Add guide button -> menu_toggle
Fix support for logitech f310 on windows
add more variants of the 360 pad and third-party XI pads
add madcatz pad
Merge pull request #302 from pinumbernumber/master

Fix support for Logitech F310 pad on windows
(OSX) Support video_monitor_index and audio_device settings
(OSX) Add system key items to the settings menu; fix a few warnings
(OSX) Only allow numeric input for integer and float settings
(OSX/iOS) Consolodate key map tables and binding routines
[Android] bump version number
(Apple) Start to clean the objective-c code
(OSX) Clear state when a gamepad is disconnected while running; any newly connected pad will occupy the lowest open slot
(OSX) Improvements:
	Pause emulation while settings window is open
	Allow negative numbers to be input in the settings list
	Don't crash when changing a setting value to an empty string
[EMSCRIPTEN] add custom input driver, removes SDL dependency + adds mouse support
[EMSCRIPTEN] undo SDL workarounds no longer needed
[EMSCRIPTEN] chrome fixes
Merge pull request #303 from libretro/emscripten

Emscripten/Javascript port