User stories for things we might want flocker to be able to do

Story: https://github.com/ClusterHQ/flocker/issues/236
To focus our efforts, as many of these as possible should be related to the example configurations @ferrantim was talking about.  We're actually going to make those work - if those are the same as these, then we'll actually make these work too.  If not, these will just be stories we tell with no particular relationship to reality.