Make FakeAuthorizer.AuthClient logic the same as apiserver.srvRoot
AuthUnitAgent now derives from fa.Tag
Revert "AuthUnitAgent now derives from fa.Tag"

This reverts commit 000b546cd121991834c552ff20fa4b202a0c122a.
Revert "Make FakeAuthorizer.AuthClient logic the same as apiserver.srvRoot"

This reverts commit 57bb51a8ab3b6032f377627a003765aa315a6f51.
state/apiserver/testing: remove unused field
Merge pull request #444 from davecheney/170-state-apiserver-testing-drop-unused-field

170 state apiserver testing drop unused field

Arguably `LoggedIn` was supposed to mean _this authoriser has authenticated an entity_ but it doesn't actually do anything.

Each `state/apiserver/...` test diligently sets the `LoggedIn` field which has no effect on the `FakeAuthoriser` nor is its state checked by any tests.