dc-js/dc.js — pull request #715 by jcamins (2014-09-24 16:43:57+00:00)
Title: Allow filters equal to 0 in filter printer

Prior to this patch, if you were filtering on the value 0, the default
filter printer would not display it, so you could end up with, for example,
", 0.05" in the controls when it should actually say "0, 0.05". This patch
checks explicitly for undefined and null filters.

(this fixes issue 714)