Controller plugin

Gamepad, tracks the button press and release works like
FlxG.justPressed, etc.
GamepadManager, manages the controlls and does auto mapping.
GamepadMapping, let you create your own mapping.
Controller, added multiple IDs support for better auto mapping support.
Fixed POV and rename wind direction to dpad direction.

GamepadManager to plugin folder.
FlxAnalog and FlxVirtualPad to ui folder.
Update fetch, prepare to merge to master.

Disabled library loader for android. It doesn't find it.
Clean Gamepad
Fixed remove listener from Controller on destroy