Separate the sync queue from the server state.

This structure controls the order of the calls in the servers, we
protect it more easily and control it in different situations.
Open the correct display in the server.
Use the sync_queue correct API instead of the internal one.
Modify the access and names of the sync_queue functions.
Simplify the data structure handling of the sync_queue.
Simplify the sync_queue lock and call.
Separate pilot_server from server for the refactor.
Refactor the pilot client functions and some fixes.