Added getCheckpoint and setCheckpoint functions to checkpoints.py
Merge branch 'vehicle_refactor_2014' of https://github.com/robotics-at-maryland/tortuga into vehicle_refactor_2014
Pipe checkpoint states added
Save a checkpoint above a pipe, it will store the assumed location of the
next pipe if given a distance.
other state will goto a checkpoint from another pipe checkpoint.
Merge branch 'vehicle_refactor_2014' of https://github.com/mxlan/tortuga into vehicle_refactor_2014