Since all scripts run in a sandbox with their own global environment,
it means that they don't interfere with each other's global variables.
Therefore, all file-wide variables can be declared global without
any change in behavior. In my understanding, it is better to do so
because this means that any code accessing those variables is going
to access them directly from the global environment table with a simple
lookup rather than having each variable referenced in the local closure
of each function separately.
Syslog calls this level "notice" and I prefer it because we use it
to display significant messages that are not warnings, but they
are not really "standard", as GLib wants them to be. There is nothing
"standard" about log messages in general.
Also, make these notice messages be enabled at debug level 2, together
with warnings. The default log.level is 2 and it is a good idea to show
notices by default too.
Finally, show them in the log with "N" and also change criticals to be
shown with "E", meaning "error"... Then promote G_LOG_LEVEL_ERROR
messages to be shown with "F", meaning "fatal", because in fact these
messages are always fatal and always call abort(). Still, keep the term
"critical" in the functions to make sure that whoever uses them is aware
that this level is only for critical conditions and not suitable to
display any kind of error.
This patch also moves nested configuration objects that are not considered
settings from the wireplumber.settings section to its own configuration
section (eg the rules array, the spa plugin properties, etc...). This allows
those objects to be merged with other same sections defined in other files.
Most of the configuration settings have a default value when they are loaded by
the Lua scripts if they are not present, so we leave them commented in the
configuration. This will make the configuration smaller when supporting layered
configuration, as all the commented sections will be part of the override files.
Currently v4l2 nodes will get higher priority than libcamera ones.
The default can be changed, of course, with wpctl.
Things are still not great if a camera is enumerated by both monitors.
The first node to be linked will grab the device and the second one
from the other subsystem will fail to negotiate.
