Added conversion from Handshake to NetworkMessage and vice versa

Added a new ConnectionCode - Close
TcpServer: AddToClientsList and AllocateID are now called add_to_clients_list and allocate_id respectively and are now private, removed SendHandshake method - we now use SendMessage method and the HandshakeToNetworkMessage method in the Handshake class
Added a new method to Utility::StringConverter - FromString
Changed NetworkMessage conversions to allow Handshake conversions
NetworkMessage: if subject is 1 then the NetworkMessage is a handshake
I may be missing something but im going to check it
I may be overcomplicating this but i want to make it as simple as possible xD

include/VoidNetServer.hpp

@@ -9,6 +9,8 @@
 
 struct VoidNetServer
 {
+	void StartServer(uint16 port);
+	void StopServer();
 private:
 	TcpServer server;
 };