Refactor code to use virtual width/height

[PixelsCommander]

At the moment we have scale-independant X,Y for objects but their width, height depends on real size of images used.

So for scale 4 it will be 32_32 and for scale 1 it will be 8_8.

It`s not good for game logic development, all game logic have to be independant of scales.

We have to modify DisplayObject code to have 8*8 always, but also implement realWidth and realHeight properties to use for rendering.