Part 1 - Respawning every 30mins.

Allow people to respawn (return to the menu) every 30mins after death, or ghost.

To do- option to user ban respawns, and stop respawns on certain antags/roles.

code/datums/mind.dm

@@ -61,6 +61,7 @@
 	var/datum/language_holder/language_holder
 	var/unconvertable = FALSE
 	var/late_joiner = FALSE
+	var/lastrespawn = 0
 
 	var/force_escaped = FALSE  // Set by Into The Sunset command of the shuttle manipulator