pulp/pulp — pull request #1445 by beav (2014-12-18 18:18:47+00:00)
Title: 1171278 - additional helper method for finding units

The fix for RHBZ 1171278 in pulp_rpm needs to be able to find a unit based on the
unit key, regardless of which repo its in. This patch adds
`find_unit_by_unit_key` to the SearchUnitsMixin to facilitiate this.

**NOTE**: this should not be merged until after 2.4.4 is released!