joomla/joomla-cms — pull request #3138 by CrandellWS (2014-02-17 18:06:06+00:00)
Title:  Menu Class Suffix

this has cause problems such as described here: http://forum.joomla.org/viewtopic.php?f=708&t=789859

Many people have mentioned putting a space before the class "nav-pills" this is the reason that is needed.