remove colon syntax from oop

sim/port.lua

@@ -1,3 +1,4 @@
+
 PortTypes = {
 	output = 0,
 	input = 1
@@ -16,7 +17,7 @@ Port = {
 	logictype = 1,
 }
 
-function Port:new(type, direction, position, causeupdate)
+function Port.new(self, type, direction, position, causeupdate)
 	local o = {
 		type = type,
 		direction = direction,
@@ -31,35 +32,35 @@ function Port:new(type, direction, position, causeupdate)
 	return o
 end
 
-function Port:setstate(state)
+function Port.setstate(self, state)
 	if state ~= self.state then
 		self.state = state
-		sim:queuegroup(self.group)
+		Simulation.queuegroup(sim, self.group)
 	end
 end
 
-function Port:setinputstate(state)
+function Port.setinputstate(self, state)
 	if state ~= self.state then
 		self.state = state
 		if self.causeupdate then
-			sim:queuegate(self.gate)
+			Simulation.queuegate(sim, self.gate)
 		end
 	end
 end
 
-function Port:getconnectionposition()
+function Port.getconnectionposition(self)
 	local offset = PortDirections[self.direction]
 	return {self.position[1]+offset[1], self.position[2]+offset[2], self.position[3]+offset[3]}
 end
 
-function Port:isrising()
+function Port.isrising(self)
 	if self.group == nil then
 		return false
 	end
 	return self.group.state and (self.group.updatetick == sim.currenttick)
 end
 
-function Port:isfalling()
+function Port.isfalling(self)
 	if self.group == nil then
 		return false
 	end