- fixed a bug that crashed the programm when a popup button was scrolled.

- fixed a bug that caused incorrect drawing position of the popup indicator.
- fixed a bug that prevented selecting no item (-1) in a popup button.
- an assertion will be raised if the program tries to select a popup button
  item that is beyond the total number of items present in the popup button.
- changed names of functions for SplitView to be consistent. Some contained
  SubView while other Subview. Now all have Subview.

src/main.c

@@ -49,6 +49,7 @@
 #include "xmodifier.h"
 #include "defaults.h"
 #include "session.h"
+#include "dialog.h"
 
 #include <proplist.h>