ipython/ipython — pull request #4159 by minrk (2013-09-01 23:00:50+00:00)
Title: don't split `.cell` and `div.cell` CSS

`.cell` matches non-IPython things that it shouldn't (inside highlighted code), everything `.cell` should match in IPython is a div.

I know we have bigger CSS scoping issues to deal with, but this is an easy fix for an obvious problem.

backport for 1.1