Also use a common pool for all nul-content ones.

2008-01-15  Behdad Esfahbod  <behdad@gnome.org>

        * pango/opentype/*:
        HarfBuzz was relicensed to a more generous and simpler license.
        Adapt.  See pango/opentype/COPYING for the new license which is
        LGPL-compatible.

2007-11-07  Behdad Esfahbod  <behdad@gnome.org>

        * pango/opentype/*: Some more cleanup and merging.

2007-10-24  Behdad Esfahbod  <behdad@gnome.org>

        * pango/opentype/*: Rename ftglue.c to harfbuzz-impl.c and more
        type renames and moving code around.

2007-10-24  Behdad Esfahbod  <behdad@gnome.org>

        * pango/opentype/*: New header file harfbuzz-global.h.  Rename
        FT_* int types to HB_* types.

2007-10-11  Behdad Esfahbod  <behdad@gnome.org>

        * pango/opentype/*: Mark internal symbols as HB_INTERNAL and
        define that to static in harfbuzz.c.

        * pango/opentype/harfbuzz-buffer-internal.h: New file.

2007-10-11  Behdad Esfahbod  <behdad@gnome.org>

        Bug 485621 – Get rid of freetype memory allocator in harfbuzz

        * pango/opentype/*: Remove all occurences of FT_Memory.  Use
        malloc/realloc/free directly.

        * pango/pango-ot*: Update to above.

2007-10-10  Behdad Esfahbod  <behdad@gnome.org>

        Bug 485559 – Boston Summit HarfBuzz optimizations

        * pango/opentype/*: HarfBuzz hacking to:

          - Rename last remaining FT_Err stuff to HB_Err.

          - Fix a couple invalid table paths to be permissive so
            fonts work better.  Particularly GDEF table for Nafees
            Nastaliq is loaded and works great now.

          - Optimize harfbuzz buffer to not copy/swap for simple
          one-to-one and "copy" GSUB operations.

        * pango/pango-ot*: Update to FT_Err to HB_Err renaming.