Make Vocaluxe buildable and playable on GNU/Linux

Build with MonoDevelop or make.
Summary of the biggest changes:

* Correct for case differences between System.Data.SQLite and
  Mono.Data.Sqlite
* Exclude Direct3D and DirectSound from linux builds
* Provide linux versions of some windows-specific build events
* Exclude VocaluxeTests from linux builds so xbuild will work
* Add ability to build the native PitchTracker on linux
* Fix some problems with acinerella module
* Fix some windows-specific dependency checks that fail on linux
* Set OpenGL color format to 24-bit on linux

Vocaluxe/CProgrammHelper.cs

@@ -98,6 +98,7 @@ namespace Vocaluxe
 
         public static bool CheckRequirements()
         {
+#if WIN
             if (!_IsVC2012Installed())
             {
                 CLog.LogError(
@@ -119,7 +120,8 @@ namespace Vocaluxe
                     true, true);
                 return false;
             }
-             * */
+            */
+#endif //TODO: check for dependencies on linux?
             return true;
         }