removing Sylvain's patch because it breaks more than it fixes unfortunately, re-issuing a bugfix release 5.8.1
removed DEBUG code and added 2010 to the copyright list
applied Ryan Zheng's patch and re-releasing 5.7.2
fixed the layout symbol bug reported by Nibble (but using a different approach as he suggested)
- optimised drawbar() and arrange() handling for multiple monitors, arrange only arranges the relevant monitors when applicable, same with drawbar
- need to release 5.7.1
switching to release flags