markers in the sequencer

- added a new redraw type - REDRAWMARKER, at the moment this draws the same windows as REDRAWANIM, but this may not always be true, and it is more explicit whats 
happening, This replaced 5 or so draw calls in quite a few places.

source/blender/src/header_sound.c

@@ -269,11 +269,7 @@ static void do_sound_markermenu(void *arg, int event)
 			break;
 	}
 	
-	allqueue(REDRAWTIME, 0);
-	allqueue(REDRAWIPO, 0);
-	allqueue(REDRAWACTION, 0);
-	allqueue(REDRAWNLA, 0);
-	allqueue(REDRAWSOUND, 0);
+	allqueue(REDRAWMARKER, 0);
 }
 
 static uiBlock *sound_markermenu(void *arg_unused)