Improved watched robot animation

Offsets due to robot height operational (again).
Improved training of dropping on backside

But also see Issue #30.
Fixed bug in maintaining new_created_widgets

When dereferencing a path to a resource the copy produced is now added
to the newly_created_widgets.
Fixed a bug recording pick up actions

Wrong copy was being added to newly_created_widgets.
Improved training robots to drop widgets

The dropped widget now records the action so if added to top-level
backside it will be added by unwatched robots (unless subsequent actions
change things).