remove proc/tan and proc/arctan since they are now reserved procs in byond version 513.1501.

code/WorkInProgress/Railgun.dm

@@ -206,9 +206,6 @@ proc/Get_Angle(atom/ref, atom/target,startpx,startpy,endpx,endpy)
   else if(dx<0)
     .+=360
 
-proc/arctan(x)
-  var/y=arcsin(x/sqrt(1+x*x))
-  return y
 
 proc/DrawLine(atom/Start,atom/End,LineType,Icon,Whole_Icon_State = "",CenterOfIconStart=1,CenterOfIconEnd=1,HalfStart_Icon_State = "HalfStart",HalfEnd_Icon_State = "HalfEnd",Layer=OBJ_LAYER,ExtraDetection=1,startpx,startpy,endpx,endpy,startpx2,startpy2,PreloadedIcon=null)
 	if(isturf(Start)||isturf(End))
@@ -407,9 +404,7 @@ proc/line_ReturnEfficDir(Angle)
 		ReturnedDir = WEST
 	return ReturnedDir
 
-//This returns the tangent of x, for use with North and South straights.
-proc/tan(x)
-	return (sin(x)/cos(x))
+
 
 //This returns the tangent reciprocal of x, for use with East and West straights.
 proc/tanR(x)