During the migration the automated script to update the copyright
headers accidentally got rid of some of the existing copyright lines.
Reinstate them.
Refactoring to pass the device ID (in addition to the user ID) through
the presence handler (specifically the `user_syncing`, `set_state`,
and `bump_presence_active_time` methods and their replication
versions).
Simplify some of the presence code by reducing duplicated code between
worker & non-worker modes.
The main change is to push some of the logic from `user_syncing` into
`set_state`. This is done by passing whether the user is setting the presence
via a `/sync` with a new `is_sync` flag to `set_state`. If this is `true` some
additional logic is performed:
* Don't override `busy` presence.
* Update the `last_user_sync_ts`.
* Never update the status message.
Part of #9744
Removes all redundant `# -*- coding: utf-8 -*-` lines from files, as python 3 automatically reads source code as utf-8 now.
`Signed-off-by: Jonathan de Jong <jonathan@automatia.nl>`
