Multi-result search view updates

* Adds ListResultsActivity to isolate action bar and backstack concerns.
* Re-uses ListResultsFragment inside ListResultsActivity rather than adding to BaseActivity.
* Simplifies options menu and backstack hackery in BaseActivity.
* Updates search result list view.
:question: we doing hipster annotation now ;) I am fine with that ... do you have intellij settings that don't make that annoying? And we should slowly but surely migrate all of our code to that for consistency