Added support for multiplayer.

Reactored code, clumped together variables in PlayerDefinition.h.
Integrated server with entity system.

include/Engine/Network/PlayerDefinition.h

@@ -0,0 +1,11 @@
+#ifndef PlayerDefinition_h__
+#define PlayerDefinition_h__
+#include <string>
+
+struct PlayerDefinition {
+    unsigned int EntityID;
+    std::string Name;
+    boost::asio::ip::udp::endpoint Endpoint;
+};
+
+#endif