Use Init() for all screens, so we can set state before the base class

members are loaded--they'll see resets, score finalization, etc.  It
also results in smaller code, due to a g++ bug that causes constructors
to be emitted several times.

stepmania/src/ScreenStage.cpp

@@ -24,6 +24,12 @@ const ScreenMessage	SM_PrepScreen		= (ScreenMessage)(SM_User+0);
 REGISTER_SCREEN_CLASS( ScreenStage );
 ScreenStage::ScreenStage( CString sClassName ) : Screen( sClassName )
 {
+}
+
+void ScreenStage::Init()
+{
+	Screen::Init();
+
 	m_bZeroDeltaOnNextUpdate = false;
 
 	SOUND->StopMusic();