make edge direction more obvious in visualization
attempt to implement an auto recover strategy, when nodes are not connectable without destroying previous connections
refactor edge directions. Represented by an array now. Also: Every node has an edge to hold a connection to an object node.
new testcase for error case T-shaped trajectory
skip first node when servicing next node of interest.
Merge remote-tracking branch 'max/master'
Merge remote-tracking branch 'upstream/master'
use new edge array instead of id_north etc.
Merge remote-tracking branch 'max/master'
set merge and dist thresh equal. also update positions
Merge remote-tracking branch 'max/master'
update heading every 45degrees
Merge pull request #50 from mlosch/master

Make graph less susceptible to spam and noisy data