Rename "facets" -> "faceting" in search funcs.

To avoid confusion with "facets" in search result sets.
Add faceting param to CloudSearchQuery.
Return Subreddit objects from subreddit_facets().
Use SearchQuery in subreddits_by_topic.
Stop stripping unicode characters from subreddits_by_topic.
Add a random jitter to accounts_activity metric.
Modify display of accounts_active info.

This now relies on the fudged number from subreddit.py for obscurity.

Rewords the default text, and title text of the metric.

Adds a "fudged" class to the block so that low values can be hidden through CSS.
Add accounts_active information to the JSON template.
Add error message to OAuth2 invalid redirect URI failure.
Refactor /api/v1/authorize error handling.
Pass the state value in OAuth2 error redirects.
Refactor state value passing to OAuth2 error responses.
OAuth client/token relationships with Accounts

Update the models to be able to update and query:

 - Which OAuth2Clients are developed by a user?
 - Who are the developers of an OAuth2Client?
 - What OAuth2AccessTokens are outstanding for a user?

There's some duplicated code here, and tests are needed, but it's
functional.
Tweaks to OAuth2 models.

Adds the clients-by-user lookup, deletion of clients, and renames
some classes and methods to be more consistent.
Navigation for "apps" tab on preferences.

Adding some controller code and template for the apps tab.  Currently
just a skeleton.
Fix AttributeError on OAuth2Client.deleted.
Add API methods for managing apps.
Start building view for managing apps.
Creating and updating apps now works.
Implement revoke/remove/delete buttons on /pref/apps.

These are ynbuttons, which cannot appear within an existing form.
Thus the "delete app" link appears in an awkward place and the
"remove developer" link currently won't work at all.  chromakode
said he was going to take a look at modifying ynbutton to fix this.

This commit fixes a bug in the OAuth2Client.delete().