Include the fallback sources in the build, and update
src/Makefile.sources so that it can be read by the CMake build files.

Fix a typo in the DirectWrite configure option so that we can properly
enable DirectWrite builds.

Also, when building the utility program, install them as well.

Unhooked. Untested.

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.

Supports enumerating variation axes, normalizing values, etc.

hb_font_get_glyph_extents now works for color bitmap fonts.
Currently only font having index format 1 and image format 17
is supported.

This adds to the autotools build system so that the (experimental)
DirectWrite support for HarfBuzz is built (and dist'ed).

This moves all the source listings in src/Makefile.am,
src/hb-ucdn/Makefile.am and util/Makefile.am into separate Makefile
snippets, so that they may be shared between different Makefile-based
build systems, such as NMake for Visual Studio.