The + flag registers a remote ID; the - flag unregisters ID.
Registering allows the MobiLink Listener to address push notifications by referencing that remote ID.
When device tracking information is uploaded successfully, registered IDs are retained in the ml_listening system table on
the server. You only need to register the ID once.
Use the -t option multiple times to register or unregister multiple IDs. Registering multiple IDs is useful for addressing
push notifications to multiple remote databases.