Clear table

A way-too-big branch, with lots of changes.
This is what I just demoed to D with the fully-automated table clearing (using ORK) and the shared autonomy table clearing using Grabcut.

For the ipython notebooks, it'll be easier to look review them here:

http://nbviewer.ipython.org/github/SharedAutonomyToolkit/shared_autonomy_perception/blob/clear_table/random_snippets/clear_table.ipynb

http://nbviewer.ipython.org/github/SharedAutonomyToolkit/shared_autonomy_perception/blob/clear_table/random_snippets/moveit_pick.ipynb