Fixed bug in dragging top-level backside

Caused by recent changes to widget sides.
Fixed a bug in watching a robot pick up a copy
Fixed a bug in birds leaving boxes

Introduced by support of multiple top-level backsides
Fixed a watched robot bug

When robot drops something on a bird -- the robot didn't wait for the
bird to finish.
Fixed another watched robot bug

When robot drops a nest with an egg it wasn't waiting for the bird to
hatch.
Improved error message

And doesn't do type check if !TT.debugging. (Should become the general
rule.)
Improved error reporting and handling

And if debugging=1 in the URL parameters the user is alerted to internal
errors (only a few re-programmed to use  this). Also abstracted testing
for the value of URL parameters.
Fixed another watched robot bug

It didn't wait for numbers to combined by Bammer. Also added better
error handling.
Better error reporting throughout
Fixed a bug in resetting local storage

It now explicitly removes the keys when reset=1 is in the URL
parameters.