[db] Block neighbors no longer cache values - dynamically calculated now
[db] all objects in SpacerContainer now have _release() methods
[db] moves ros system graph updating functionality direclty into the RSG
[db] this just got moved into ros_topology, saved here for now
[db] fixes to getting rid of objects in qtview
[db] saved state
[db] updates the rostest program
[db] DrawingBoard refactored to be known as TopologyWidget
[db] ros_diarc now uses TopologyWidget too!
[db] seperates the notion of the RosSystemGraph and the
LiveRosSystemGraph
[db] adds a callback mechanism to the LiveRosSystemGraph update
[db] adds some documentation commenting to the top of the topology
[db] moves functionality in TopologyWidget.autoLayout() to
new_object_callback in ros_diarc, which allows new nodes to be added
into the graph on refresh. This breaks the qtview demo's, which need to
be fixed now.
[db] removes rosgraph_hooks.py - functionality moved to ros_topology
[db] deletes commented out DrawingBoard code
[db] fixes qtview examples, removes reminants of depricated autoLayout
[db] several bug fixes - including band reordering bug.