Overview Description:
On the BiDi local, the Up (Ctrl-Up, PgUp) and Down (Ctrl-Down, PgDown) keys
move thumb of rtl GtkHScale in the wrong direction

Steps to Reproduce:
1. Run testgtk program in ./gtk+-2.2.x/tests on a BiDi locale (e.g. he_IL)
2. Press `range controls' button.
3. Set focus on GtkHScale widget.
4. Change value of GtkHScale using one of Up/Down keys.
   The thumb moves to reverse direction. <-- Problem!!

Actual Results:
Thumb of GtkHScale is moved to the left with *Up keys and to the right
with *Down keys

Expected Results:
Thumb of GtkHScale should be moved in the direction of Home with *Up keys.
It should be move in the direction of End with *Down keys.
When GtkHScale has rtl direction, Home is from the right and End is from
the left.

Additional Information:
We think the following steps would fix this issue.
1. Open gtk/gtkrange.c and see gtk_range_scroll().
2. When GtkScrollType is GTK_SCROLL_STEP_UP, GTK_SCROLL_STEP_DOWN,
   GTK_SCROLL_PAGE_UP or GTK_SCROLL_PAGE_DOWN, Delete the following code:

   |  if (should_invert(range))
   |     call_something()
   |  else

However, after the above-mentioned steps are applied, PageUp/PageDown keys
cannot move the thumb.
The reason why they can't do is that they are interpreted twice.
(On non-Bidi locale, the thumbs moves every other places.)
  PageUp:   GTK_SCROLL_PAGE_LEFT and GTK_SCROLL_PAGE_UP scroll types
  PageDown: GTK_SCROLL_PAGE_RIGHT and GTK_SCROLL_PAGE_DOWN scroll types

If this double handling itself is designed behavior, we suppose
the value of the last argument of add_slider_binding() for PageUp/Down
should be replaced at gtk_scale_class_init() in gtkscale.c:
  PageUp:   GTK_SCROLL_PAGE_LEFT  --> GTK_SCROLL_PAGE_BACKWARD
  PageDown: GTK_SCROLL_PAGE_RIGHT --> GTK_SCROLL_PAGE_FORWARD