* Add general_reconnectonlytoconnected setting.
* Replace last_device_address shared prefs string with
last_device_addresses shared prefs string set.
Bluetooth address of a device is added to last_device_addresses when
connecting to the device.
Bluetooth address of a device is removed from last_device_addresses only
when deleting the device or explicitly disconnecting from the device
(e.g. by selecting "Disconnect" in the device tile menu).
* Adjust ExternalPebbleJSActivity to better support multiple connected
devices.
* If setting enabled, add source application (or SMS)
* Fallback to using notification subject if body is unavailable
* Trim/cut sender or title at 25+ chars if necessary
* Better support for notifications without body or subject
Implement reading battery percentage.
Implement setting temperature scale used on clock display.
Communication protocol taken from: https://github.com/h4/lywsd02
Davis MosenkovsandJosé Rebelo
