New API:
+hb_face_collect_unicodes
+hb_face_collect_variation_selectors
+hb_face_collect_variation_unicodes

New API:
HB_UNICODE_MAX

New API:
+hb_face_builder_create
+hb_face_builder_add_table

New API:
+hb_font_get_glyph_advances_for_direction

New API:
+hb_font_funcs_set_glyph_h_advances_func
+hb_font_funcs_set_glyph_v_advances_func
+hb_font_get_glyph_h_advances
+hb_font_get_glyph_h_advances_func_t
+hb_font_get_glyph_v_advances
+hb_font_get_glyph_v_advances_func_t

This reverts commit 0c1b287b.

Add the fuzzer test case for feature collection timeout.

This new API returns cvXX and ssXX related NameId, things like
featUiLabelNameId, featUiTooltipTextNameId, sampleTextNameId, ... of cvXX
and UINameId of ssXX, in a unified way.

However HarfBuzz currently doesn't expose an API for retrieving the actual
information associated with NameId from the `name` table and that should be
done separately.

Simply, it returns the number of faces on a font blob.

To be used on hb-sanitizer tool but other clients also
can benefit from it.

New API:
- hb_set_previous()
- hb_set_previous_range()

New API:
- hb_blob_copy_writable_or_fail()

When the font size or variations settings on underlying FT_Face change,
one can call hb_ft_font_changed() and continue using hb_font created using
hb_ft_font_create().

Fixes https://github.com/behdad/harfbuzz/issues/559

New API:
hb_ft_font_changed()

New API:
hb_font_set_ptem()
hb_font_get_ptem()

Needed for hb-coretext optical sizing:
https://github.com/behdad/harfbuzz/issues/360

We're not going to define public macros for tags for tables.
There's little use to those and they are implementation detail.

The 'avar' table does not allow random access to axis maps,
so change API to avoid quadratic-time implementation.

Removed -hb_ot_var_normalize_axis_value(), added
+hb_ot_var_normalize_variations() and
+hb_ot_var_normalize_coords() instead.

With this, I believe MATH table API is not ready to be merged.

Now it is just reporting one error about “503 undocumented or incomplete
symbols”, that will be the easy part I guess.

Some of it (create, reference, destroy) are adapted from Cairo docs.

HB_VERSION_CHECK's comparison was originally written wrongly
by mistake.  When API tests were written, they were also written
wrongly to pass given the wrong implementation... Sigh.

Given the purpose of this API, there's no point in fixing it
without renaming it.  As such, rename.

API changes:

  HB_VERSION_CHECK -> HB_VERSION_ATLEAST
  hb_version_check -> hb_version_atleast

Move it to new harfbuzz-gobject library.  Implement enums and
boxed types for object-types.  Still have to do boxed types for
value types.

Makes documentation / introspection easier.

That moment that you have to accept that you made API mistakes...

Initial setup of gtk-doc. Straight forward setup following the gtk-doc
instructions. Ignore some troublesome types in src/hb-gobject.h. To
build use "./autogen.sh --enable-gtk-doc" then "make". Docs are in
harfbuzz/docs/reference/html/index.html.