The new config system in pcb-rnd
Priority is an integer property of each config root.
Syntax-wise it is part of the name of the config
root. In the lihata config file it is either specified or omitted. When
omitted, a role dependent default value is
used. The default values are chosen in an intuitive way, thus most
commonly the priority value is omitted.
For scalar settings, the highest priority
value determines the final value of a setting after the merge. If there
is a tie, role decides: the role closer to the CLI is stronger.
For lists and arrays, priority determines the
order of merge, which changes the order of items in the final list as
config roots prepend and append items.