ipython/nbconvert — pull request #120 by minrk (2013-04-03 20:56:12+00:00)
Title: band-aid to avoid figure collision

The figure counter is not global, so a cell with multiple outputs, followed by
another cell with outputs will result in clobbered figures.

This is a band-aid fix to avoid collisions on cells with less than 100
figures, until the proper state is handled.