Duplicate `production.rb` and add `staging.rb`.
Added survey name to the list of responses header
Dragging-and-dropping a question in the same position has no effect.

Use the `update` event to hook into the drag-and-drop instead of `stop`.
Removed settings_pane move method and its references
Removed whitespace and semicolon
Made the overlay cover the full screen
bug fixes
Added logo
Changed category content type from string to text
Showing an overlay when re-ordering sub questions under question with options and categories.
Show survey details on the settings pane when a question is deleted (instead of a blank settings pane).
Merge branch 'master' into develop