documentation: Move __init__ docstrings to classes

*  Documentation renders by default with class
   init. params. in headline.  Since special
   methods are also generally hidden, it reads
   better if all init param docs are put in
   class-level docstring.

*  Commitments have been made to continuing this project
   officially, so removed warning message from beginning
   of docs and index.

Signed-off-by: Chris Evich <cevich@redhat.com>
Signed-off-by: Lukáš Doktor <ldoktor@redhat.com>
Signed-off-by: James Molet <jmolet@redhat.com>
dockercmd: Raise Except. if subargs is a string

Signed-off-by: James Molet <jmolet@redhat.com>
dockertest: Mass-docstring + pep8 fix/cleanup

Signed-off-by: Chris Evich <cevich@redhat.com>
dockertest: Minor cleanups

*  Fully deprecated OutputGoodBase.output_good and
   updated unittests.

*  Officially declared environment.AllGoodBase.__init__
   as abstract.

*  Removed unnecessary TODO comment

Signed-off-by: Chris Evich <cevich@redhat.com>