So suppressing notifications by either the launcher status or service
status can be enabled/disabled together with the re-connect tweaking. This
makes more sense than having it unconditionally enabled and makes the
presence of the feature (and when it is effective) also more visible to
users.
Add new SyncthingLauncher class which lauches Syncthing
under the hood via external SyncthingProcess or using
libsyncthing.
Note: Launching via libsyncthing is still experimental.
First step of refactoring compution of high-level
notifications to prevent code duplication for compution
of "disconnected" and "sync complete" events.