Use python logging for loguserdata.py, log to console

Python logging is configured with a stream handler and should
also replicate the previous logging to 0600 /var/log/heat-provision.log

By logging to a stream handler cloud-init will write to its log,
which will show up in the server console log. This means that heat
provisioning can now be monitored without needing to log in with:

nova console-log <servername>

This change also touches the file /var/lib/heat-cfntools/provision-finished
instead of also writing a datestamp to it, which is redundant.

Change-Id: Id0312bd2216a83753df601b17ad16d5355cdb11d
Merge "Use python logging for loguserdata.py, log to console"