Use python logging in install / log cherrypy at right severity

Use python logging in install / log cherrypy at right severity

This replaces the print statements in the installer code with
a python logger so we can log all output to the installer log
and a subset of it to stdout in one step without duplication.

The cherrypy.log.error() logs to the "error" log at a severity
of logging.INFO by default. Set an appropriate log level for
these as well.

https://fedorahosted.org/ipsilon/ticket/35

Signed-off-by: Rob Crittenden <rcritten@redhat.com>
Reviewed-by: Simo Sorce <simo@redhat.com>