UP-4008 / IP:65: Reapplied Universality functionality to Respondr

Moved relevant CSS from layout-portlet.css and portlet.css (universality) into the selectEntities.jsp in order to use the same functionality for categories/groups.Also updated markup to include Bootstrap classes for mobile-responsiveness. Added a few general overrides for Respondr into content.less.
What's this change?  Doesn't look related to the ticket.  (This one also is much harder to parse the meaning of... is this stuff that came in by merging from master?)