Fixed 2d z-sorting.
Fixed 2d z-sorting.

ovieira/TouchScript,RainsSoft/TouchScript,gdos/TouchScript,zhutaorun/TouchScript,zodsoft/TouchScript,RainsSoft/TouchScript,ovieira/TouchScript,zodsoft/TouchScript,zodsoft/TouchScript,ovieira/TouchScript,RainsSoft/TouchScript,zhutaorun/TouchScript,gdos/TouchScript,zhutaorun/TouchScript,gdos/TouchScript