Ensure that all member attributes are initialized

I ran the game through cppcheck and it spat out a bunch of member
attributes that weren't being initialized. So I initialized them.

In the previous version of this commit, I added constructors to
GraphicsResources, otherlevelclass, labclass, warpclass, and finalclass,
but flibit says this changes the code flow enough that it's risky to
merge before 2.4, so I got rid of those constructors, too.

desktop_version/src/Music.cpp

@@ -132,6 +132,9 @@ void musicclass::init()
 	songEnd = 0;
 
 	Mix_HookMusicFinished(&songend);
+
+	mmmmmm = false;
+	usingmmmmmm = false;
 }
 
 void songend()