now cloning texture options to allow usage of the same instance multiple times in one queue
added 'repeat' property to TextureOptions constructor
to avoid overloading time-based animations, the maximum delta is now truncated (closes #500)
added 'touchGroup' property to containers, similar to 'mouseChildren' (closes #348, refs #83)

better late than never, right? ;-)
updated asdoc description (refs #348)