Changed the internal of EventDispatcher. It is now using the Invoker class to improve performance.
    For generic delegates (using dynamic invoke), event dispatch is now more than two times faster (even with method using default and variadic parameters).
    If the delegate type is known at compile time (and proper addEventListener is called), event dispatch is more than 10 times faster.
    Some compiler changes will be needed for the proper addEventListener() to be called when method is known at compile time - This is unfortunately due to issues related to aot.