bring gobjs and canvases into focus for errors, add animations

Pretty simple feature to always bring error objects into focus when the "error" link is clicked.

Same for the edge-case where the canvas itself is the culprit.

In each case we do a short web animation.

I'm not exactly sure how to integrate the web animations with styles. We should probably figure that out before merging. Quick-and-dirty would be to attach and detach a class in a timeout, but that seems ugly...