Pr/870 suggestions

These two commits reformat the docs somewhat, remove spurious tests with max_iter and simplify the code in a few spots.  They also change the output to a tuple of two dicts instead of a dict of two dicts.  

Still needed:  The docs don't describe what the parameter k is.  The also need a description of what gets returned.

It'd be great to get a name to go with MIMAC and PWP.  Even the papers don't give a reason for calling it PWP or MIMAC.