The setting is saved on a file in:
/settings/relayTimings.json
Then during bootup, it's read and restored.
Settings can be set via MQTT command on Topic:
vesoer/*dev-id*/control/settings/relayTimers
using a json format.
{ "b1":50, b2...}
where b1 is Bell 1, b2 Bell 2, etc..
A new Melody Struct was added containing the melody's main attributes.
The MQTT Topic Subscriptions were updated to a more proper format.
Also added DEV_ID that corresponds to the device's ID or Serial Number.
Chnaged the Deserialization function to actually adjust the MelodyStruct's attributes.
Added basic play/stop functionality.
