Implementation of Shape Renderer

More info about shapes: https://github.com/e-ucm/ead/wiki/Renderers#shapes 
The class ShapesFactory generates pixmaps (images) for any type of shape. It can be handy for other purposes.

To see shapes in actions, you can execute class [EngineTechDemo](https://github.com/e-ucm/ead/blob/master/engine/desktop/src/test/java/es/eucm/ead/engine/java/tests/EngineTechDemo.java?source=cc)