harvard-lil/perma — pull request #743 by jcushman (2014-11-17 19:22:12+00:00)
Title: Simplify group updates.

This just simplifies user group updates using Django's m2m array assignment syntax.

(I made these changes while messing around with mirroring propagation. Don't think they actually made propagation more efficient the way I hoped, but they're nicer to read anyway so what the heck.)