The planners:

(i) AStarSkeleton.py comes from 133b HW#1, running directly on a grid.
    But updated for ROS and to run backwards (from goal to start), in
    case the start is moving.  Please FIX the distance and other
    costs!!

(ii) prm_mattress.py is straight from 133b HW#3.  You'll have to
     remove the visualization and update for our map, etc.  Also note
     it was originally written for python 3, though the differences
     are small (see Ed Discussion for a post).

The moveskeletonv2.py adds two features: (a) it publishes the
waypoints for RVIZ - nice to see and debug.  You will need a MARKER
display in RVIZ to see.  And (b) it checks whether the TF library is
properly set before starting.  Else startup (could) trigger temporary
TF errors, always annoying.

Added the skeleton for the move node.  Please update as needed, in
particular to (1) command the robot to move to a point, (2) include a
planner, (3) udpate the obstacle map.