Update timeutils.py from oslo

This fix is related to oslo-incubator commits:
3bc6f79d794aee9d51abc0be10e846b971fae847
af76064855c5bb888e1a0d2800d1f49470e19091
df3f2bafbe76d78d017d40e7dc08909fee7dbe34

Change-Id: I1194df94d85d3dde29e81003c0c3db735c66b35f
Merge "Update timeutils.py from oslo"
xenapi: post install scriptlet to rpm

A freshly installed XenServer requires some modifications in order to be
able to run OpenStack. Nova contains an rpm specification to create a
package with the dom0 plugins, however installing the rpm is not enough.
Some more actions need to be taken:
 - create /images, link to a directory within the local SR
 - setup an ssh keypair, and authenticate it with the host
This change adds a post script to the nova plugins rpm spec file, so
by installing the rpm on a XenServer, it is ready to run OpenStack, no
further manual actions needed.

Change-Id: Id57e3a3ab2782550468c6aa4c01059ceb7cc81ab