started	kratos;	many fixed bugs

kratos will ultimately enforce our permissioning everywhere.
Right now, pulls our groups/perms from gh.com, and builds an
internal model.

improved core/backends - they return the gh_id and ghe_id when a
user is first signed up through gh/ghe. removed the hackiness of
adding this info during	syncing.

moved user model from core to kratos.

idded nifty iter_get helper function to	github client. It will
seemlessly page	     through	     items returning   them one by one.

switched to pluggable auth model everywhere
fixed kratos view generating output json
fixed bug: repo perms now show up
added ungrouped repos to output