changelog
    
    
    - Wed, 16 Oct 2013 23:07:59 +0300
 
    - by Santeri Piippo <crimsondusk64@gmail.com> [Wed, 16 Oct 2013 23:07:59 +0300] rev 507
 
    - reworked the ring finder algorithm greatly, tries harder to find the optimal solution
 
    - Wed, 16 Oct 2013 19:34:12 +0300
 
    - by Santeri Piippo <crimsondusk64@gmail.com> [Wed, 16 Oct 2013 19:34:12 +0300] rev 506
 
    - Added last-resort ring draw with quads
 
    - Wed, 16 Oct 2013 17:11:16 +0300
 
    - by Santeri Piippo <crimsondusk64@gmail.com> [Wed, 16 Oct 2013 17:11:16 +0300] rev 505
 
    - Ring draw: maintain separate polygons for the ring circles and draw them separately of the ring fill to prevent artifact lines from being drawn