Integrate with uci to support 'enabled/disabled' startup option and
override netify's default auto network selection.
config netifyd
option enabled 0
option autoconfig 1
autoconfig: Use netify's in-built interface selection
else use 'internal/external_if' definitions.
Also persist important agent config across sysupgrade
agent.uuid, serial.uuid, site.uuid
Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
