Modified detector node for parade.

Changed node to publish bool.
Modified c code.

Fixed function signature. Added num_edge variable to let python quickly
create the resultant edge list.
Updated _get_edges function

Modified get edges to make use of the ctypes wrapper. Should be faster.
Added goup_points call to node
Merge branch 'parade-obstacle-node'

Conflicts:
	obstacle_detector/src/detector_node.py