Server/Player Connection implementation

+ Mud.Models.IPlayer
+ -- Namespace changed from Mud.Models to Mud.Models.Characters
+ -- Added IGame property requirement.

+ Mud.Engine.Models.Character.Player
+ -- Implemented ReceiveData method. Not tested but is supposed to
accept input data from the client and store it.
+ -- ReceiveData method stores a reference to the currently running
IGame object.

+ Mud.Engine.Engine Settings now has a "Player" property for setting the
default Type used to instantiate player objects during run-time.

+ Mud.Engine.networking.IServer
+ -- Connections property Type changed from IPlayer[] array to
List<IPlayer> collection.
+ -- Deleted Update() method requirement.
+ -- Modified Start() method to require IGame parameter.
+ -- Deleted Connect(Socket) method requirement.
+ -- Added IGame property requirement.

+ Mud.Engine.Networking.Server
+ -- Adjusted class to reflect changes made to IServer.
+ -- Start method now properly waits for incoming connections and passes
them off to a new Instance of a IPlayer object.

+ Mud.Engine.Networking.ConnectionState
+ -- New interface required to be implemented by objects needing to
receive data from the server. It is not explicitly required yet, but
will be in a future commit by having the Server check to ensure the
IPlayer object has the required contract.