One of the issues raised with keystoneclient plugins is the way that
loading of a plugin is mixed in with the definition of a plugin. Amongst
other things this really meant that there was only one way to utilize
each plugin class, to do another plugin that utilized an existing one
you would have to define a new class and proxy to it.
In this patch we split the concerns. There is a whole new section called
loading that is solely responsible for ways to load the auth plugin from
CLI or from argparse and other future methods.
This new section will likely be split into its own repository.
Change-Id: I8387b86fc0e3a8403f9806440196e8723eaf1ee4
efcadd6937