Add an optional function to the pop-up button, so that it will select the next entry when clicked and also do some miscellaneous code clean-ups including forward declarations.

rtgui/wavelet.cc

@@ -21,6 +21,7 @@
 #include <cmath>
 #include "edit.h"
 #include "guiutils.h"
+#include "rtimage.h"
 
 using namespace rtengine;
 using namespace rtengine::procparams;