Converted to Holonomic Robot

Robot now has independent control of vx and vy
Holonomic Hybrid Automaton

Changed hybrid automaton robot to holonomic drive. Obstacle avoidance works better now.
mild cleanup

used temp variable for obst_distance
used np.linalg.norm instead of writing own
enabled plotting of map
improved comments
started test suite for robot.py
refactored robot and robot_ha
Refactored navigator.py

policies now return a desired velocity, which Robot.vcontroller converts to a control velocity.
Cleaned up ogmap.py
deleted robot_det.py

base class is now deterministic
Cleanup for probabilistic localization code

switched from (vr, vphi) to (vx, vy, vphi)
transposed ensemble data structures
updated tests