ran 'chmod -x' on many files

Merged in community contributed controller mappings from https://raw.githubusercontent.com/gabomdq/SDL_GameControllerDB/master/gamecontrollerdb.txt

Added common controllers used with Steam Big Picture

These are entirely untested
Several USB ids refer to multiple packaged products. In those cases I tried to use the most common name, or a general name (e.g. PS3 Controller), or a completely generic name (e.g. USB gamepad) if it wasn't clear what type of controller it was.
Patches welcome!

Don't crash on exit from SDLActivity if we don't have a singleton for some reason. (Thanks Rachel!)

Track android device panel width & height as well as window surface & height.

Expand SDLActivity::SDLSurface::surfaceChanged() callback to grab the panel width and height at the same time and pass that along to the native code. Only works on API 17+. Duplicates surface dimensions whenever it fails.

Add Android_DeviceWidth/Android_DeviceHeight globals to native code.
Disambiguate Android_ScreenWidth/Android_ScreenHeight -> Android_SurfaceWidth/Android_SurfaceHeight
Use device width/height for all display mode settings.

Added support for the PS3 controller driver in PlayStation Now

Added Android hardware feature support to the default manifest

Added improved mouse pointer capture under API 26. (Thanks Rachel!)

Added SDL_IsChromebook() to determine if we're running on a Chromebook.

Add Android support for relative mouse mode to SDL.