It is better to have type-specific event names to minimize the amount
of constraint string matches we do on hooks, as most hooks (if not all)
are interested on specific types of objects only.
Similarly, use a different object manager for each object type to
minimize the performance impact of iterations and lookups, as all
such actions are interested in only 1 object type every time.
Port all existing hooks to the new event names and the get-object-manager API.
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.
Persistent profiles will never change. This can be useful if we want to keep
a specific device profile even if a new one with higher priority becomes
available. For example, keep the 'off' profile instead of switching to best
profile when monitor screens is resumed.
See #138
