Preparing for the next tutorial!

-Added the Entity class, includes several optimization tools for entity
iterations.
-Enhanced the SerializableObject structure to handle basic operators and
to be easier to manipulate.
-Added a main loop for all entities in every Channel.
-Implemented the custom message protocol on the server
-Added a Extension.cpp file with basic events to allow people to
customize the serverside easily.
-Added a few math tools such as Vector3 and Vector3i