Content search skips empty folders, and other fixes

Fixes

• Searching Content no longer lists folders that hold nothing matching your search.
• Deleting an installed app now updates the playlists and the Content page that referenced it right away, instead of after a manual reload.
• Changing your account email now rejects an address you cannot use, your current one or one already taken, on the field itself rather than after sending a confirmation code.
• A screen you have revoked now resets cleanly instead of retrying against an error.

Improvements

• Quick actions on Home, Now playing links and links in notifications move you through the dashboard instantly rather than reloading it.
• Screenly support accounts no longer count toward your plan’s member limit.