Initial conversion to RecyclerView.

Still working on some animation stuff (requires a few Simperium updates).
Use `findFirstVisibleItemPosition()` to match other RecyclerViews in the app.
Use Simperium 0.6.2
Added animations when moderating/deleting/spamming a comment.

Still sorting out how to get animations working well onNetworkChange from Simperium.
Merge branch 'develop' into issue/2061-notifications-recyclerview
Cleaned up a few warnings.
A modify change type should still update the list.
Merge branch 'develop' into issue/2061-notifications-recyclerview
Set `setHasStableIds()` in the notes adapter.

Removed the override in `CursorRecyclerViewAdapter` since we'll always use a subclass and they can decide to use stable ids or not.
We can use notifyDataSetChanged when deleting/moderating comments with the addition of using stable Ids.

This will automatically animate the change.
Hide the header view when hiding a notification.

Fixes issue where header would animate out after the change came back through Simperium.
Scroll to the row that is about to animate so it can be seen.
Added background color to each row item to fix weird animations.

Removed background from recycler view to save on overdraw.
Merge pull request #2085 from wordpress-mobile/issue/2061-notifications-recyclerview

Convert Notifications List to use RecyclerView