Merge pull request #3 from JimmyDeemo/master

Fix for FlxExtendedSprite dragging.
FlxBitmapFont angle caching
Create license.txt
removed FlxDelay since it duplicates FlxTimer class and less effective
Compile fix for FLX_NO_KEYBOARD
Compile fix for FLX_NO_MOUSE
Create new mouse and touch packages in system.input
Update for FlxG.touches.getFirst()
FlxButtonPlus: Fix for FlxSpriteGroup change
Move flickering logic from FlxObject to FlxSpriteUtil
Move FlxSpecialFX to flixel-addons
Introduce 'FlxPlugin' as the base class for all plugins
FlxControl: Now extends FlxPlugin, move it into flixel.addons.plugin