Adding classes to notify on change of network connection.

Thanks https://github.com/tonymillion/Reachability.
It's actually a modification of the official Apple classes of
the same name, except the Apple library only worked in the
simulator (for me). This one works on a real device too.
Network notification working.

Added a short status notification over the grid toggle
button. Changes indicator on change in network status and
changes ability to submit a digit. If offline, just say so
instead of make the url request.