redraw tray (if dirty) even if hidden. On wince at least this

prevents the bottoms of the tiles from peeking out from under a
partially obscuring board, giving away information.  In cases where
the board completely hides the tray this is unnecessary, but making
that optimiztion can come later.  This is a bug.

xwords4/common/tray.c

@@ -140,7 +140,7 @@ drawTray( BoardCtxt* board )
             }
 #endif
 
-            if ( (board->trayVisState != TRAY_HIDDEN) && dictionary != NULL ) {
+            if ( dictionary != NULL ) {
                 XP_Bool showFaces = board->trayVisState == TRAY_REVEALED;
                 Tile blank = dict_getBlankTile( dictionary );