Reduce code duplication in Phortune account controllers
Ref T12451. This is a GREAT comment (A++) but we only need one copy of it.
This uses a pattern similar to Projects, which is a little weird but works well enough.
- Viewed all four tabs of an account.
- Viewed a page with a bad account ID which 404'd properly.
Reviewed By: chad
Maniphest Tasks: T12451
Differential Revision: https://secure.phabricator.com/D17694