twbs/bootstrap — pull request #13999 by SteelyWing (2014-07-01 02:57:43+00:00)
Title: fix affix leave `position: relative` when unpin issue

when using `offset({top: x})` to set top, that will change `position` to `relative` (see [here](http://devdocs.io/jquery/offset#offset-functionindex--coords)), if not remove the inline css `relative`, it will override affix `fixed` css.