remotingSerializer should be compatible with haxe.Serializer

[postite]

//remotingSerializer
public static function run(...):String{} //returns String
//haxe.Serializer
public static function run(...) // no return

both functions should have same return types or php7 throws error 500 at runtime ..

i leave it here i'll do a pR later.

[postite]

also dir &direction arguments should be optionnal