Make ceilometer play better with EPEL packages

Ceilometer now builds correctly without specifying specific python
libs via the spec file.  Added an epoch component for wmse to
prevent EPEL from stepping on the needed/installed package and
breaking yum updates.

Change-Id: I0e3f4023bdd3c065bd132d2a45c885ab3232f9b8
Merge "Make ceilometer play better with EPEL packages"