Improved interaction editing

[GoogleCodeExporter]

Rather than having a second page for customizing interactions, each interaction 
should have an in-line editor as part of the actual exploration editor page 
(rather than having a 2 page modal for interactions, you just select the 
interaction and then edit it on the exploration editor page).

Beyond this change in workflow, the in-line interaction editor should give a 
better preview of what the interaction will look like, rather than having a 
flat picture or some other editor representation (like a schema editor). 
Consider multiple choice, for instance. Adding options to multiple choice 
should be sort of in the form:

Option A
Option B
________

Where the line can be typed in and immediately added. It would visually look 
like the multiple choice interaction does to learners.

Original issue reported on code.google.com by [email protected] on 23 Jul 2015 at 1:14