Implement Core.TickCount

Convert movement, actions (lift/use), combat, and spells to use Core.TickCount and avoid DateTime caveats (performance, system time dependency, etc)
Refactor DateTime.Now to DateTime.UtcNow
Add LOS check for Iron Maiden addon

Scripts/Accounting/AccessRestrictions.cs

@@ -31,7 +31,7 @@ namespace Server
 					Console.WriteLine( "Client: {0}: Past IP limit threshold", ip );
 
 					using ( StreamWriter op = new StreamWriter( "ipLimits.log", true ) )
-						op.WriteLine( "{0}\tPast IP limit threshold\t{1}", ip, DateTime.Now );
+						op.WriteLine( "{0}\tPast IP limit threshold\t{1}", ip, DateTime.UtcNow );
 	
 					e.AllowConnection = false;
 					return;