Updated to MonoGame 3.6 + Directory refactor

- Barotrauma's projects are in the Barotrauma directory
- All libraries are in the Libraries directory
- MonoGame is now managed by NuGet, rather than referenced from the installed files (TODO: consider using PCL for easier cross-platform development?)
- NuGet libraries are not included in the repo, as getting the latest versions automatically should be preferred
- Removed Content/effects.mgfx as it didn't seem to be used anywhere
- Removed some references to Subsurface directory
- Renamed Launcher2 to Launcher

Libraries/Lidgren.Network/NetPeer.Discovery.cs

@@ -0,0 +1,69 @@
+using System;
+using System.Net;
+using System.Threading;
+
+#if !__NOIPENDPOINT__
+using NetEndPoint = System.Net.IPEndPoint;
+#endif
+
+namespace Lidgren.Network
+{
+	public partial class NetPeer
+	{
+		/// <summary>
+		/// Emit a discovery signal to all hosts on your subnet
+		/// </summary>
+		public void DiscoverLocalPeers(int serverPort)
+		{
+			NetOutgoingMessage um = CreateMessage(0);
+			um.m_messageType = NetMessageType.Discovery;
+			Interlocked.Increment(ref um.m_recyclingCount);
+
+			m_unsentUnconnectedMessages.Enqueue(new NetTuple<NetEndPoint, NetOutgoingMessage>(new NetEndPoint(NetUtility.GetBroadcastAddress(), serverPort), um));
+		}
+
+		/// <summary>
+		/// Emit a discovery signal to a single known host
+		/// </summary>
+		public bool DiscoverKnownPeer(string host, int serverPort)
+		{
+			var address = NetUtility.Resolve(host);
+			if (address == null)
+				return false;
+			DiscoverKnownPeer(new NetEndPoint(address, serverPort));
+			return true;
+		}
+
+		/// <summary>
+		/// Emit a discovery signal to a single known host
+		/// </summary>
+		public void DiscoverKnownPeer(NetEndPoint endPoint)
+		{
+			NetOutgoingMessage om = CreateMessage(0);
+			om.m_messageType = NetMessageType.Discovery;
+			om.m_recyclingCount = 1;
+			m_unsentUnconnectedMessages.Enqueue(new NetTuple<NetEndPoint, NetOutgoingMessage>(endPoint, om));
+		}
+
+		/// <summary>
+		/// Send a discovery response message
+		/// </summary>
+		public void SendDiscoveryResponse(NetOutgoingMessage msg, NetEndPoint recipient)
+		{
+			if (recipient == null)
+				throw new ArgumentNullException("recipient");
+
+			if (msg == null)
+				msg = CreateMessage(0);
+			else if (msg.m_isSent)
+				throw new NetException("Message has already been sent!");
+
+			if (msg.LengthBytes >= m_configuration.MaximumTransmissionUnit)
+				throw new NetException("Cannot send discovery message larger than MTU (currently " + m_configuration.MaximumTransmissionUnit + " bytes)");
+
+			msg.m_messageType = NetMessageType.DiscoveryResponse;
+			Interlocked.Increment(ref msg.m_recyclingCount);
+			m_unsentUnconnectedMessages.Enqueue(new NetTuple<NetEndPoint, NetOutgoingMessage>(recipient, msg));
+		}
+	}
+}