fixes a typo in the stow arm script.

The typo was first noted on 1/12/2013, but the fix was overwritten.
The arm's name is irb_120, not irb-120.
This caused the "Could not find requested planner..." error
Made stow arm script wait 10 seconds between resending goals.
Updated joint limits on arm.
Stow arm now correctly reports success.
Started a script to drop objects in the bin.

Currently, the inverse kinematics fail, which is unsurprising
considering how hard it is to get into the position required
to drop things in the bin.

Next step is to try a better ik solver.