Design changes

Although it is working fine, the graphics (video) module needs some restructuring before adding new features. I would like to work with other graphic programmers in this aspect.

In the other corner, the EXE code is also going to have some minor changes. For example, for clarity all the Game Object classes will have CG before its class name (and in the filename): CGElement, CGActor, CGPlayerControl, etc.

All these changes are going to be included on the next file release, version 0.10.