investigate ways to use filters so that not there is no
information overload in the view. Can't display too
many nodes at once.
instead there should be a possibility to only display
nodes that are less then distance n away from the
selected node. And an indication where nodes have been
cut off so that the user can expand the graph or
explore it by selecting another node.
functionality:
1) show nodes up to chosen level from selected node.
show a plus sign on leaf node if they have more
connections.
2) focus on selected node and automatically expand
nodes that are now within the threshold level.
* Another idea to reduce the number of nodes in the
view would be the application of the mylar filter to
the view.
see
https://sourceforge.net/tracker/index.php?func=detail&aid=1488727&group_id=164823&atid=833236
