IFTTT Key length increase to 50 characters

Updated the key length to 50 to accomodate newer ifttt keys.

OTA Updates and UI improvement

Added the feature to allow over-the-air updates from a browser.
Improved the look of the User Interface.

Update to fix issue where home assistant triggers automation on restart

Added additional MQTT topic to publish the battery level. Sent with retain flag in order for Home Assistant to recall this value on restart.

Default topic for battery level: doorbellsensor/status/battery
Payload: JSON Document with batt as the battery level

Main MQTT topic is sent without the retain flag.

Default topic for main topic: doorbellsensor/status
Payload: "ON"

Initial Release

Support for MQTT
Support for IFTTT
Configuration Portal