bug fix css/textformat
- added clone feature/function
- added dispose function
- added margin left/top/right/bottom. the margins reflect how many
	pixels are leftover around the rectangle of the scale9 rectangle used
	for the texture
added a comment to the static function hex2css
- changed the use of xml attribute "frame" width, height, x and y.
	smaller, trimmed png textures can be used.