WIP: Convert vertical XModule to pure XBlock.

@cpennington  These are the changes we had to make to get VerticalModule running as a pure XBlock in the LMS - still raises in Studio. 

@nasthagiri @itsbenweeks FYI
The Studio view is different from the author view (confusingly). The Studio view is for editing the xblock, the author view is for viewing it in Studio.