FlxTypedButton: change status to a property that updates alpha rather than manually set alpha every frame.
Merge branch 'dev' of https://github.com/HaxeFlixel/flixel into dev
Merge branch 'dev' of https://github.com/HaxeFlixel/flixel into dev

Conflicts:
	flixel/ui/FlxTypedButton.hx
Merge branch 'dev' of https://github.com/HaxeFlixel/flixel into dev
Put in some null checks that fix crash bugs in flixel-ui when popups close (closing a FlxSubState in response to a button click can lead to situations where an object is destructed halfway through its update function, leading to null reference errors)
Merge branch 'dev' of https://github.com/HaxeFlixel/flixel into dev
Merge branch 'dev' of https://github.com/HaxeFlixel/flixel into dev

Conflicts:
	flixel/FlxG.hx
	flixel/ui/FlxTypedButton.hx
Merge branch 'dev' of https://github.com/HaxeFlixel/flixel into dev
Merge branch 'dev' of https://github.com/HaxeFlixel/flixel into dev
Merge branch 'dev' of https://github.com/HaxeFlixel/flixel into dev
Added Magenta to FlxColor and put in null check + IFlxDestroyable to FlxText
Add FlxTypedSpriteGroup
Merge branch 'dev' of https://github.com/HaxeFlixel/flixel into dev

Conflicts:
	flixel/text/FlxText.hx
	flixel/util/FlxColor.hx
Merge branch 'dev' of https://github.com/HaxeFlixel/flixel into FlxTypedSpriteGroup

Conflicts:
	flixel/group/FlxSpriteGroup.hx
FlxTypedSpriteGroup: opimization via statically typed _sprites array
FlxTypedSpriteGroup: also use _sprites for reset()
Make MouseEventManager compatible with FlxObject, closes #823
Fixing weird stage offset issue when toggling fullscreen in flash.
Storing last FlxGamepadButton state.
Increase the dev branch version to 3.3.0