Adding Model comments/rating feature.
Model comments/ratings are enabled using the Fivestar and Rate modules.
Fivestar enables the fivestar rating widgets, and the Rate module enables
the "Did you find this review useful?" widget.

Current setup is based on comments for a given model version, which are then
averaged for the version, and all ratings for all versions averaged for the
whole model.
Moving model comment javascript to module and changing section wording.
Javascript to hide and expose the model comments form is now located in
the module rather than the OpenABM theme. Changing wording of the
comments section to "Comments & Ratings".
Merge branch '7.x-2.x-dev' into 7.x-2.x