Added method to set sync_teams
Renamed lookup_account to get_sync_account

I like having a name that specifies exactly what we're looking up,
especially since I'm going to add more rules for youtube accounts.
Reworked get_sync_videos logic for youtube videos

The new logic matches the old logic better.

Refactored the tests a bit.  Put the tests against is_for_video_url()
with the tests for get_sync_account().  These methods should use the
same logic, so testing them both makes sense.
Renamed "is_for_video_url" -> "should_sync_video_url"

Like with get_sync_account(), I think it makes sense to have the
method name indicate that it's checking the syncing logic.
Refactor for the integration forms/formsets

Moved the logic from the AccountFormSet class to the AccountForm
classes.  This allows for a greater variety of forms.  Before there
were a lot of requirements for the form classes, now basically
anything should work.  I'd like to add some forms for youtube accounts
and they weren't going to fit with the old system.

Started using the nose assertion functions.  I like they PEP-8 syntax
and not having to type "self.".
Move youtube account add/remove logic into forms

These forms are pretty trivial at this point, but this allows us to
add more complexity for youtube accounts.  I want to add a field to
update sync_teams and this seems like the best way to do it.

Added ability for account forms to redirect to other pages (needed for
the AddYouTubeAccountForm).  Updated AccountFormset a bit.

Added field to render a button.

Removed the views tests.  We were only testing the redirect logic and
that's now tested by the forms tests.
Switched externalisets test filenames to nose syntax

I decided to stop fighting with nose and just end test modules with
_tests.  It's a bit annoying that the package is called "tests" and we
still need to add "tests" to the module filename, but it's not that
bad.

The from <module> import * was causing weird errors sometimes.
Added form field to set sync_teams

Updated template/CSS to display the widget.

Pass the user viewing the form to AccountFormset and
YoutubeAccountForm.  We need this to figure out which teams to allow
the admin to pick.

Added way to create a team and an admin member quickly in
utils.factories.

Removed unused youtube_accounts variable.