Use PortAudio-Sharp bindings for easier updates

Use COSFunctions for OS-specific stuff
Add dll directories on startup (could be done in the modules itself, but this way it avoids all trouble)

Vocaluxe/COSFunctions.cs

@@ -0,0 +1,89 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.InteropServices;
+using System.Text;
+
+namespace Vocaluxe
+{
+    static class COSFunctions
+    {
+#if WIN
+        private static bool _DefaultDllDirSet;
+        private static bool _UsePath;
+        private static bool _UseSetDllDir;
+
+        private static class CWindowsFunctions
+        {
+            [DllImport("kernel32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
+            public static extern void AddDllDirectory(string lpPathName);
+
+            [DllImport("kernel32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
+            public static extern void SetDllDirectory(string lpPathName);
+
+            [DllImport("user32.dll", CallingConvention = CallingConvention.StdCall)]
+            [return: MarshalAs(UnmanagedType.Bool)]
+            public static extern bool SetForegroundWindow(IntPtr hWnd);
+
+            [DllImport("user32.dll", CallingConvention = CallingConvention.StdCall)]
+            [return: MarshalAs(UnmanagedType.Bool)]
+            public static extern bool SetDefaultDllDirectories(int directoryFlags);
+
+            // ReSharper disable InconsistentNaming
+            public const int LOAD_LIBRARY_SEARCH_DEFAULT_DIRS = 0x00001000;
+            // ReSharper restore InconsistentNaming
+        }
+#endif
+
+        public static void AddEnvironmentPath(string path)
+        {
+            string newPath = Environment.GetEnvironmentVariable("PATH") ?? string.Empty;
+            if (newPath.Length > 0)
+                newPath += ";";
+            newPath += path;
+
+            Environment.SetEnvironmentVariable("PATH", newPath);
+        }
+
+        public static void AddLibrarySearchpath(string path)
+        {
+#if WIN
+            if (!_DefaultDllDirSet)
+            {
+                try
+                {
+                    CWindowsFunctions.SetDefaultDllDirectories(CWindowsFunctions.LOAD_LIBRARY_SEARCH_DEFAULT_DIRS);
+                }
+                catch (Exception)
+                {
+                    _UsePath = true;
+                    _UseSetDllDir = true;
+                }
+                _DefaultDllDirSet = true;
+            }
+            if (_UsePath)
+                AddEnvironmentPath(path);
+            if (!_UseSetDllDir)
+            {
+                try
+                {
+                    CWindowsFunctions.AddDllDirectory(path);
+                }
+                catch (Exception)
+                {
+                    _UseSetDllDir = true;
+                }
+            }
+            if (_UseSetDllDir)
+                CWindowsFunctions.SetDllDirectory(path);
+#endif
+        }
+
+        public static void SetForegroundWindow(IntPtr hWnd)
+        {
+#if WIN
+            CWindowsFunctions.SetForegroundWindow(hWnd);
+#endif
+        }
+    }
+}