gcode header and trailer options now use ; as a line break

Blender UI does not support multi line edit within StringProperty so for
now we use a ; as a line break marker.

scripts/addons/cam/__init__.py

@@ -547,11 +547,11 @@ class camOperation(bpy.types.PropertyGroup):
 	#g-code options for operation
 	output_header =  BoolProperty(name = "output g-code header", description = "output user defined g-code command header at start of operation", default = False)
 
-	gcode_header =  StringProperty(name = "g-code header", description = "g-code commands at start of operation", default = "G53 G0")
+	gcode_header =  StringProperty(name = "g-code header", description = "g-code commands at start of operation. Use ; for line breaks", default = "G53 G0")
 
 	output_trailer =  BoolProperty(name = "output g-code trailer", description = "output user defined g-code command trailer at end of operation", default = False)
 
-	gcode_trailer =  StringProperty(name = "g-code trailer", description = "g-code commands at end of operation", default = "M02")
+	gcode_trailer =  StringProperty(name = "g-code trailer", description = "g-code commands at end of operation. Use ; for line breaks", default = "M02")
 	
 		
 	#internal properties

scripts/addons/cam/utils.py

@@ -1159,7 +1159,9 @@ def exportGcodePath(filename,vertslist,operations):
 	for i,o in enumerate(operations):
 	
 		if use_experimental and o.output_header:
-			c.write(o.gcode_header + '\n')
+			lines = o.gcode_header.split(';')
+			for aline in lines:
+				c.write(aline + '\n')
 			
 		free_movement_height=o.free_movement_height#o.max.z+
 		
@@ -1349,7 +1351,9 @@ def exportGcodePath(filename,vertslist,operations):
 		c.feedrate(unitcorr*o.feedrate)
 		
 		if use_experimental and o.output_trailer:
-			c.write(o.gcode_trailer + '\n')
+			lines = o.gcode_trailer.split(';')
+			for aline in lines:
+				c.write(aline + '\n')
 			
 	o.duration=duration*unitcorr
 	#print('duration')