Fix missing stale query option
Fauxton: Add view filter

This allows a module to register an extension to filter out what views
should be displayed in the side bar.
An example of usage is to only display views that have
"language:javascript"
Fauxton: Remove settings.json.dev

We don't use this file and its causing confusion with new contributors.
The grunt task look for a `settings.json`, if it doesn't find that it
defaults to settings.json.default