Correct version.py and update current version string

Correct the version string in setup.cfg for Icehouse.

Make ironic/version.py use PBR instead of the stale code that was there.

Make ironic/common/config.py properly set the version string so that
all CLI commands output it when "--version" is passed.

Remove openstack.common.version module which is no longer present in
oslo-incubator.

Closes-bug: #1294389

Change-Id: I9a7bfe5fc1b79934cf2467d6f8a6c16f41205dbf
Merge "Correct version.py and update current version string"