Khan/khan-exercises — pull request #23965 by xymostech (2012-06-14 22:29:04+00:00)
Title: Fix up exercise: Congruent Angles

Make the framework more general for congruency exercises overall. Also, move around some utils so that I don't have to name the congruency one something stupid.

sandcastle for updated congruent_angles: http://sandcastle.khanacademy.org/media/castles/xymostech:congruency/exercises/congruent_angles.html

@beneater @spicyj @mwittels review