Adds "linked_to_centcomm" variable to maps.

- Obviously, by default, this will be one.
- Adds new event where the link with central command is broken for
- Admins can make or break the link with Central command Indefinitely with the secrets panel
- You cannot do the following while the link is broken: Call the shuttle / Recall the shuttle / Fax Central command / Recieve messages from Central command / Send messages to Central Command / Call or Send the Cargo Shuttle
- An admin may send a message to the crew even when the link is broken, but he will be prompted first asking if he is sure.
- Blob alerts ignore whether or not the link with central command is broken

code/modules/admin/topic.dm

@@ -2338,6 +2338,14 @@
 				log_admin("[key_name(usr)] made all SMESs powered", 1)
 				message_admins("<span class='notice'>[key_name_admin(usr)] made all SMESs powered</span>", 1)
 				power_restore_quick()
+			if("breaklink")
+				log_admin("[key_name(usr)] broke the link with central command", 1)
+				message_admins("<span class='notice'>[key_name_admin(usr)] broke the link with central command</span>", 1)
+				unlink_from_centcomm()
+			if("makelink")
+				log_admin("[key_name(usr)] created a link with central command", 1)
+				message_admins("<span class='notice'>[key_name_admin(usr)] created a link with central command</span>", 1)
+				link_to_centcomm()
 			if("activateprison")
 				feedback_inc("admin_secrets_fun_used",1)
 				feedback_add_details("admin_secrets_fun_used","AP")