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

makefile

@@ -0,0 +1,12 @@
+windowsLibs = Output/gstreamer-sharp.dll Output/glib-sharp.dll
+all:
+	$(MAKE) -C PitchTracker
+	$(MAKE) -C Vocaluxe/Lib/Video/Acinerella
+	rm -f $(windowsLibs)
+	xbuild /property:Platform=x64 /property:Configuration=ReleaseLinux
+
+clean:
+	xbuild /target:Clean
+	$(MAKE) -C PitchTracker clean
+	$(MAKE) -C Vocaluxe/Lib/Video/Acinerella clean
+	git checkout $(windowsLibs)