neuronstagingarea.js: fix error in checking for 'vis' argument.
graph_widget: fix typo.

This flash-based widget to be deleted.
compartmentgraphwidget (aka new js-only graph widget): fix mouse bindings.

* shift+click: select skeleton
* alt+click: toggle visibility of skeleton in the 3d viewer.
submitter: handle empty or null text or json, and report more on error.
Merge remote-tracking branch 'origin/master'