Set infinite scroll enabled in bookmarks after fetching each page.

Infinite scroll is now disabled after fetching the last page of bookmarks even if there's more than one page.

This also fixes a problem where deleting a bookmark would incorrectly disable
infinite scroll. It's not perfect -- deleting a bookmark then loading the next
page will "lose" a bookmark until a reload - -but it's closer.
Update Crashlytics framework.
Fix awful:// URLs tapped in e.g. Awful Beta opening in Awful.

If multiple installed apps register the same URL schemes, it's nondeterministic
which one gets called by iOS. So let's skip iOS's routing for internal awful:
URLs.

The problem persists for other apps that open awful: URLs, but we can't really
fix that.
Hide sidebar when opening a thread from an awful: URL.
Hide separators after the last cell in thread lists.