Rearrenged the directory tree

I just _had_ to get rid of that horrible libs/ directory. Now most of the
graphical stuff is in client/, but I'll create more subdirectories so that
they're not getting in the way.

common/udp_network_utility.hpp

@@ -0,0 +1,79 @@
+/* Copyright: (c) Kayne Ruse 2013
+ * 
+ * This software is provided 'as-is', without any express or implied
+ * warranty. In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ * 
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ * 
+ * 1. The origin of this software must not be misrepresented; you must not
+ * claim that you wrote the original software. If you use this software
+ * in a product, an acknowledgment in the product documentation would be
+ * appreciated but is not required.
+ * 
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ * misrepresented as being the original software.
+ * 
+ * 3. This notice may not be removed or altered from any source
+ * distribution.
+*/
+#ifndef UDPNETWORKUTILITY_HPP_
+#define UDPNETWORKUTILITY_HPP_
+
+#include "SDL/SDL_net.h"
+
+class UDPNetworkUtility {
+public:
+	UDPNetworkUtility() = default;
+	~UDPNetworkUtility() = default;
+
+	void Open(int port, int packSize);
+	void Close();
+
+	//bind to an available channel
+	int Bind(const char* ip, int port) {
+		Bind(ip, port, -1);
+	}
+	int Bind(IPaddress* add) {
+		Bind(add, -1);
+	}
+
+	//bind to certain channel
+	int Bind(const char* ip, int port, int channel);
+	int Bind(IPaddress* add, int channel);
+	void Unbind(int channel);
+
+	IPaddress* GetIPAddress(int channel) {
+		return SDLNet_UDP_GetPeerAddress(socket, channel);
+	}
+
+	int Send(const char* ip, int port, void* data, int len);
+	int Send(IPaddress* add, void* data, int len);
+	int Send(int channel, void* data, int len);
+	int SendAll(void* data, int len);
+	int Receive();
+
+	void* GetOutData() const {
+		return reinterpret_cast<void*>(packOut->data);
+	};
+	void* GetInData() const {
+		return reinterpret_cast<void*>(packIn->data);
+	};
+	UDPpacket* GetOutPacket() const {
+		return packOut;
+	}
+	UDPpacket* GetInPacket() const {
+		return packIn;
+	}
+	UDPsocket GetSocket() const {
+		return socket;
+	}
+private:
+	UDPsocket socket = nullptr;
+	UDPpacket* packOut = nullptr;
+	UDPpacket* packIn = nullptr;
+};
+
+#endif