juju/juju — pull request #828 by dimitern (2014-09-24 11:11:35+00:00)
Title: EnvironTag from the API connection is accessible to all facades

Refactoring a few places to allow easier access to the current
API connection's environment tag, and a few drive-by fixes:
- HighAvailability API's NewClient() no longer needs EnvironTag
as a (string) argument, but discovers it via the connection.
- MetricsManager API refactored slightly to use an AuthFunc to
verify any given tags are valid environment tags and match
the current environment.
- api.Uniter() factory method changed to validate the currently
authenticated user's tag is indeed a names.UnitTag, rather
than possibly panicking when it's not.
- api.Info.EnvironTag is now names.EnvironTag, rather than
a names.Tag; tests changed accordingly.
- Minor drive-by fixes to imports ordering and doc comments.