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

PitchTracker/makefile

@@ -0,0 +1,20 @@
+objects = \
+	compatibility.o \
+	dywapitchtrack/dywapitchtrack.o \
+	dywapitchtrack/ptDyWa.o \
+	FFT/FFT.o \
+	FFT/RealFFTf.o \
+	Helper.o \
+	performous/pitch.o \
+	ptAKF.o \
+	PitchWrapper.o
+
+CPPFLAGS = -std=gnu++11 -fPIC
+
+PitchTracker: $(objects)
+	gcc -shared -o libPitchTracker.dll.so -fPIC $(objects)
+	strip libPitchTracker.dll.so
+	cp libPitchTracker.dll.so ../Output/
+
+clean:
+	rm -f ../Output/libPitchTracker.dll.so libPitchTracker.dll.so $(objects)