Added shared collection "clear".
Added clear message to player list.
Added clear handling to player_list.
Fixed client::player_list trying impossible join/leave.
Shared collections are now identified using strings.
Credentials can now be linked (inference).
Missing const in netcom_base.
server::instance now gives net and log to states.
Update configuration.
config::shared_state is now working.
Updated usage of config::state
Added test server state
Added test state
WIP on configuration state
Added example credential link
Ignored GDB temporary files