Wow.  Broke so much stuff.  Now largely works again.  Stalking doesn't work.  Need to make recentering non-blocking.
Merge branch 'advanced'

* advanced:
  Wow.  Broke so much stuff.  Now largely works again.  Stalking doesn't work.  Need to make recentering non-blocking.
Improved wall and robot collision response. Stalking now working and very creepy.
Merge branch 'advanced'

* advanced:
  Improved wall and robot collision response. Stalking now working and very creepy.