Revamped XML for the last time, and added ability to save XML.
Toying with supervisor update
Added validation, but only for systems with the lxml module installed.
Added color to all simobjects
Added color parsing to the XMLParser and simulator
Added color to the interface
Tabified robot docks by default
Nicer management of dock windows
Merged with physics branch
dock expand on title click
Keep dock positions on rewind
Merge branch 'rainbow_robots' into stage
Merge branch 'stage' into supervisorplay
Updated the avoidobstacles
Nothing
Adjusted zoom
Merge branch 'stage' into supervisorplay
Switched to RelaxNG validation, because it's way better.
Fixed unit tests for the new XML parsing code somebody else added.
Updated simulation.rng.