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

Barotrauma/Launcher/Program.cs

@@ -0,0 +1,26 @@
+#region Using Statements
+using System;
+using System.Collections.Generic;
+using System.Linq;
+#endregion
+
+namespace Launcher
+{
+#if WINDOWS || LINUX
+    /// <summary>
+    /// The main class.
+    /// </summary>
+    public static class Program
+    {
+        /// <summary>
+        /// The main entry point for the application.
+        /// </summary>
+        [STAThread]
+        static void Main()
+        {
+            using (var game = new LauncherMain())
+                game.Run();
+        }
+    }
+#endif
+}