* /war-invite :
Send an invitation to start a war. Example: /war-invite Death Hard
* /war-accept :
Accept the invitation to start a war.
* /war-reject :
Reject the invitation to start a war.
* /war-cancel-invite :
Cancel the invitation already sent to start a war.
* /war-cancel :
Finish the current war: it can only be used after 1 day of war.
Those commands can only be executed by guild leaders.
