Rhn register misc fixes (#20724)
Rhn register misc fixes (#20724)

* Remove monkeypatching of rhn config in rhn_register

rhn_register.Rhn() was doing some complicated monkeypatching of
the up2date_client.config.Config() class to add a default config
value. Since that was only used in one place, remove the monkeypatch
and handle the single default case.

That case was 'server_url' option, so replace it with a Rhn.server_url
property. Also handle the error case when no server url is provided.

* refactoring
* flatten some indention levels
* add 'enable_eus' to module doc
* set enable_eus var and use it directly
* style/pep8/etc cleanups
* some import cleanups

types was unused, os/re were from module_utils * import

* remove * import from module_utils.redhat
* remove * imports from module_utils.base
* remove unused Rhn._subscribe method
* cleanup pep8 style stuff
* remove a unused default mutable arg from Rhn.subscribe

Rhn.subscribe() only gets called in one place, and thats
with channels from module_params which default to [] and
are typed as a list.

thaim/ansible,thaim/ansible