Start adding Linux Udev joypad input.
More fixups in udev joypads.
Add force feedback.
Hook up rumble interfaces to input drivers.
Add RETRO_ENVIRONMENT_GET_RUMBLE_INTERFACE.
Add rumble tests to libretro-test.
Small cleanups.
Minor tweaks.
Fixes to force feedback.
Add udev to ./configure
Merge branch 'udev'