fixed Go function callback to remove the userdata representing the fu…

…nction from the stack before calling the actual function (to match C behavior)

added calling go function w/ argument to basic example

example/basic.go

@@ -8,6 +8,16 @@ func test(L *lua51.State) int {
 	return 0;
 }
 
+func test2(L *lua51.State) int {
+	arg := lua51.CheckInteger(L,-1);
+	argfrombottom := lua51.CheckInteger(L,1);
+	fmt.Print("test2 arg: ");
+	fmt.Println(arg);
+	fmt.Print("from bottom: ");
+	fmt.Println(argfrombottom);
+	return 0;
+}
+
 func main() {
 	var L *lua51.State;
 
@@ -23,6 +33,10 @@ func main() {
 	lua51.PushGoFunction(L, test);
 	lua51.PushGoFunction(L, test);
 
+	lua51.PushGoFunction(L, test2);
+	lua51.PushInteger(L,42);
+	lua51.Call(L,1,0);
+
 
 	lua51.Call(L,0,0);
 	lua51.Call(L,0,0);

lua51/golua.c

@@ -35,6 +35,8 @@ int callback_function(lua_State* L)
 {
 	unsigned int *fid = clua_checkgofunction(L,1);
 	GoInterface* gi = clua_getgostate(L);
+	//remove the go function from the stack (to present same behavior as lua_CFunctions)
+	lua_remove(L,1);
 	return golua_callgofunction(*gi,*fid);
 }