Add OpenGL 3.1 Core and Multi Window Support

The GLX-Extension generates now a Window with a OpenGL 3.1 Context bound
There is also detection of the Core-Version from the
OpenGL-Implementation for the Mesa-Driver
Swapping also supported so you can begin drawing on the Window
Last but not least initial Support for Multiple Render Windows
The Engine handles his own Main Window but its now possible to add more
custom Windows and draw his stuff on it with using the "CustomDraw"
Command which it could be possible to work with multiple Threads
There is no warranty that the Feature is Threadsafe