Remove pal_emergency_stop
Merge follow_planner

It is not ready for use yet.
follow_planner: Initial commit

This was forked from navigation/global_planner
It probably doesn't work as is. I haven't tried.
follow_planner: Now it builds

I can start hacking seriously now.
Merge branch 'follow-orig' into follow-planner
follow_planner: add follow goal listener
follow_planner: add logic to follow a moving goal
follow_planner: fix publishing of the plan

Also, fix node prefix for the follow_goal topic
follow_planner: cleanup headers

Among other things, remove unimplemented members
Merge pull request #1 from po1/follow-planner

Add Follow planner, a dumb global planner to follow stuff