don't list types, just apps when filtering activity
don't need format column any more
re-use class name logic from other places
fix the more results link
WIP: Filter search results based on app they report to belong to.
Issue:42 Filter search results by app
refactoring the application filter out of the search and history pages
Hide many apps with little to contribute under "system" rather than "home", "activity" and "search"
And add the new app filter to the grouped activity page