Added Xinput support
-Uses Xinput 9.1.0, requires Windows Vista, 7, or 8
-Supports wired Xbox 360 Controllers
-Needs to be enabled in control menu (controller support)
-D-pad and left stick navigates for menus
-Start button opens/dismisses menus, skips cinematics
-A button selects menu items
-B button and Back goes back
-X button deletes bindings in key binding menus
-All buttons can be bound in controls
-Stick clicking is tied to view/move configuration (swaps when stick function swaps)
-Added `xbox_usernum` - selects which connected profile is used.
-Added `xbox_stick_mode` - selects between right/left handed stick layouts
-Added `xbox_trigger_threshold` - sets trigger threshold
-Added `xbox_yaw_sensitivity` - sets horizontal view sensitivity
-Added `xbox_pitch_sensitivity` - sets vertical view sensitivity
-Added `xbox_pitch_invert` - inverts vertical axis