initial code to avoid concurrency issues plus small code cleaning

Conflicts:
	mdp_plan_exec/scripts/mdp_planner.py
adding configurable ports and dir for prism manager
buf fixes for concurrency handling

Conflicts:
	mdp_plan_exec/prism_robots
more bug fixes
Updating prism-robots which I missed from origin cherry pick.
Merge pull request #68 from hawesie/nick_concurrency

changes to handle concurrency - cherry-picked