Support several output formats in state_graph tool

This commit adds -T aka --format option to state graph tool that
can be used to specify output format. Supported values are 'dot',
'svg', 'svgz' and 'png'.

Change-Id: I27a74b582726da24a1b05d4ffb72bde860fff417
Update oslo and bring py3kcompat in

Related-bug: #1240827
Change-Id: I8f4c78f1ff1cb73fca8af9f6df8392d1636ae95f
Use py3kcompat.urlutils from oslo instead of six.urllib_parse

Six before 1.4.0 does not provide urllib_parse module, so we need
another solution.

Closes-bug: #1240827
Change-Id: I6b49b80b94028e01da0e3c4930f3e97cd32f73d0
Remove incorrect comment

Change-Id: I1944a9876c221b22f17822970d8929079c0cf5ee
Merge "Update oslo and bring py3kcompat in"
Merge "Use py3kcompat.urlutils from oslo instead of six.urllib_parse"