[HB] Add point_index to get_contour_point()
[HB] Add point_index to get_contour_point()

Pointed out by Keith Stribley on HarfBuzz list.

OpenInkpot-archive/iplinux-pango1.0,danny-ku/pango,OpenInkpot-archive/iplinux-pango1.0,kari-lentz/alpha-pango,danny-ku/pango,kari-lentz/alpha-pango,kari-lentz/alpha-pango,Distrotech/pango,OpenInkpot-archive/iplinux-pango1.0,Distrotech/pango,danny-ku/pango,kari-lentz/alpha-pango,Distrotech/pango