changelog
    
    
    - Thu, 09 Feb 2017 00:52:23 +0200
 
    - by Teemu Piippo <teemu@hecknology.net> [Thu, 09 Feb 2017 00:52:23 +0200] rev 1100
 
    - Removed all overlay support. It's a messy pile of mess and I will reimplement it later as background images and it will be much better then.
 
    - Thu, 09 Feb 2017 00:45:44 +0200
 
    - by Teemu Piippo <teemu@hecknology.net> [Thu, 09 Feb 2017 00:45:44 +0200] rev 1099
 
    - GLRenderer no longer exposes the model pointer.
 
    - Thu, 09 Feb 2017 00:43:30 +0200
 
    - by Teemu Piippo <teemu@hecknology.net> [Thu, 09 Feb 2017 00:43:30 +0200] rev 1098
 
    - LDGLData merged into GLRenderer since it only deals with one document now. GLRenderer generalised from rendering documents to models.