This removes the ability of updating service accounts through the CLI
(something we never used anyway), now that service accounts cannot be
uniquely identified by their email address.
A PUT request on /api/user/{user-id} by the user themselves would allow
too much, and would allow self-granting of roles (including admin),
group membership (so join any arbitrary project) and pretend to be
service accounts.
Refactor of pillar-server and pillar-web into a single python package. This
simplifies the overall architecture of pillar applications.
Special thanks @sybren and @venomgfx
