Implement infinite reconnect and cancel.

[gkoh]

Enable a user to cancel a connection attempt.

Merge in #132 from @hijae for the settings to control the behaviour.

With this change, the following will occur:

• with Infinite-ReConnect = OFF
  • furble will attempt a single reconnect on connection drop
  • a successful reconnect will reset the counter
• with Infinite-ReConnect = ON
  • furble will attempt to reconnect indefinitely, unless Cancel is pressed
  • M5ez menu handling doesn't help us here, the control menu will be shown, but any item press will exit