We don't want to leave the cert/key laying around in a tmp dir.  This
was missed when host.cleanup() was moved out of host.rpm() a long time
ago.

For systems we don't support with proper OS packages, a tarball is
better than nothing.  We already generate one, this just allows us to
save it rather than remove it as part of the cleanup process.

RPM remains the default package type.

When we add new package types, using rpmdir will make much less sense.

* Add missing docstrings, end all doctrings with a period
* Avoid overriding builtins (format, type)
* Don't use [] as method defaults

This is adjustable via the config with the puppetuser setting.  When
puppet runs, it resets the ownership of these files, which causes rpm -V
to show them as modified.