This implements the functionality of the owm.sh script in ucode and adds
functionality to include babel links from bird. It also ensures that we
only report the best link quality if there are multiple redundant links.
The dry-run mode was replaced with a debug option that can be enabled
using uci. To appear on the map as quickly as possible, the first update
occurs after 5 minutes, the second 25 minutes later, and then all further
updates every 30 minutes.