Fixed a bug in a robot removing a widget

remove_animation expected a side not the widget directly.
Partial fix to load sensor of a widget

Still not activated properly but at least is listening for events.
Fixed bug in JSON generation of empty hole

Due to recent changes expected to create JSON for backside widget.
Boxes have random blue shade borders

So when a box is in a box it is easier to distinguish them.
Updated compiled version
Merge pull request #120 from ToonTalk/master

Updating gh-pages to master