Cleanup superfluous.c a bit

The superfluous.[ch] files have a few minor issues, this patch addresses some of them:

- Move the defines to the top of the superfluous.c file
- Include the ifdef NORMAL_ICON_KABOOM inside the DoKaboom() function
  because the DoKaboom is used without the NORMAL_ICON_KABOOM ifdef in
  other files.
- Include the ifdef WINDOW_BIRTH_ZOOM inside the DoWindowBirth() function,
  therefore the function don't needs to be defined twice (with and whitout
  WINDOW_BIRTH_ZOOM define.
- Now the functions are defined in superfluous.h and the externs are not
  needed.
  - We need include the dock.h in the superflous.h because is used by the
    definition of MakeGhostDock().
  - We need include the superfluous.h in window.c (removing the extern)

src/window.c

@@ -57,6 +57,7 @@
 #include "xinerama.h"
 #include "appmenu.h"
 #include "appicon.h"
+#include "superfluous.h"
 
 #ifdef MWM_HINTS
 # include "motif.h"
@@ -82,9 +83,6 @@ extern Atom _XA_WINDOWMAKER_STATE;
 extern WPreferences wPreferences;
 extern Time LastTimestamp;
 
-/* superfluous... */
-extern void DoWindowBirth(WWindow *wwin);
-
 /***** Local Stuff *****/
 static WWindowState *windowState = NULL;
 static FocusMode getFocusMode(WWindow *wwin);