Update account modal to edit duration instead of sleep time.

* It's difficult to specify a sleep time if the sleep time is later
  than or equal to midnight.  Allow account update modal to edit the
  day's duration instead.  Sleep time is what's persisted however.  An
  artifact of switching currently puts a "duration" property in the
  $auth.user object, but that parameter will be filtered out when sent
  to server.

* Add "hourInput" directive for handling "Minutes" model data type and
  integer input.