- brought back hilites in buttons when mouse-over

- automatic pulldown opening can now be controlled ( user setting?)
  it has two thresholds:
  - when no menu was opened before, it waits A milliseconds
  - when (in the same block a menu was opened, it waits B millisec.
  Currently A= 0.4 sec, B= 0.1 (or so)
- 3d window header; brought back old drawtype menu (test, compare!)
- another test: the old menubutton doesnt work anymore with hold-mouse
  only, you can also use it as the other popups (old method still works)
- proposal; all buttons that pop up a block, get special drawtype (arrows)

source/blender/include/interface.h

@@ -125,6 +125,7 @@
 #define UI_EMBOSSTABM	8
 #define UI_EMBOSSTABR	9
 #define UI_EMBOSST		10
+#define UI_EMBOSSMB		11	/* emboss menu button */
 
 /* uiBlock->direction */
 #define UI_TOP		0