Remove outdated methods
Add support of new user methods such as:

:is_contact, Boolean
:contact, Hash
:snapshot, String
:snapshot_interval, Integer
:media_device_id, String
:idle_at, DateTime

(regarding to https://github.com/sqwiggle/sqwiggle-api-documentation/blob/master/objects/user.md
and few curl requests)
Update user spec for new methods support