Resource nest copying caused sharing

Nests were treated as copies incorrectly when copied from a resource.
Improved number display

When in a small area and has operator the operator was large font and
the fraction was tiny.
Display updated only for visible backside widgets
Fixed CSS of robot conditions

Were being displayed as much too tall and a bit lower than it should.
Watched robots when hidden go home

So when seen again they are where they started. Fixes #108.
Fixed robot waiting for bird bug
Animates waiting robots

Fixes #112.
Removed unneeded images
Birds morph to and from static block graphics
Ignore drops of top-level backside

If to itself or its descendants
Improved bird animation
Fixed a wrong CSS class bug

Where the parent sometimes became toontalk-being-dragged rather than
than the 'dragee'
Chained calls to JQuery
Close button clicks always closes

Sometimes was opening backside instead.
Bird animates when dragover

To indicate ready to receive what is being dragged.
Improved bird animation
Improved CSS of robot backside
Improved CSS of robot conditions area
Box contents rendered more reliably

But there are still circumstances where only re-rendering makes them
visible when in a robot's conditions.
Improve widget titles

To include descriptions together with their toString values.