Remove Fedora/libvirt workaround

An updated libvirt package to address [1] is in Fedora 20 now, so we
don't need this work-around.  Modify the comments of the other part of
the work-around (restart of services) and link to the most relevant
bug

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1098376

Change-Id: I47fba7b4f273162c2af1e37902a512041449750b
Add flag for ceilometer tests

Added flag for enable or disable tests for ceilometer
feature of fast work with databases

Change-Id: If68c2b733358a98f56265b70c31366e6a9120dfa
Merge "Remove Fedora/libvirt workaround"
Merge "Add flag for ceilometer tests"
Merge commit 'refs/changes/83/86083/2' of git://gold.eng.hq.xensource.com/git/github/openstack-dev/devstack into tmpbranch