Incidentally, this makes it not crash with icu-le-hb anymore...
I'm not smart / stupid enough to spend two more days debugging C++
linking issues, and this is ABI-stable at least.

That's really the logic desired.  Except that MONGOLIAN VOWEL SEPARATOR
is not default_ignorable but it really should be.  Reported to Unicode.

Based on suggestion from Konstantin Ritt.

Broke it when merged cmap mapping and normalizer.  Ouch!

- Unicode 6.2.0 goodness,
- Unassigned codepoints now have correct properties.  Passes test suite.

https://github.com/grigorig/ucdn

Now that we have pthread detection in configure, we don't need Glib
anymore.  Glib will only be a Unicode data provider.

If the first char in the run is a combining mark, but there is text
before the run, don't insert dottedcircle.

Part of addressing:
https://bugzilla.redhat.com/show_bug.cgi?id=858736

Now we respect Arabic joining across runs.

To be used for a variety of purposes.  We save up to five characters
in each direction.  No public API changes, everything is taken care
of already.  All clients need to do is to call hb_buffer_add_utf* with
the full text + segment info (or at least some context) instead of
just passing in the segment.

Various operations (hb_buffer_reset, hb_buffer_set_length,
hb_buffer_add*) automatically reset the relevant contexts.

Speeds up UTF-8 parsing by calling strlen().

Also move UTF routines into a separate file, to be reused from shapers
that need it.

I don't expect ragel to be creating too much noise in its generated
output, and including this in-tree helps users right now.  We can
revisit this later if it proved to be too much trouble.

On Windows we don't care whether or not we link to libstdc++.
Seems to fix build with mingw32 on msys, as reported by Werner.

Oh well...

With FreeSerif, it seems that the 'ccmp' feature does ligature
substituttions.  That was then causing syllable match failures.  We now
find syllables before any features have been applied.

Test sequence: U+0D9A,U+0DCA,U+200D,U+0DBB,U+0DCF

And hb_buffer_content_type_t and enum values.

With this in place, you can remove GDEF/GSUB/GPOS tables from Arabic
fonts and still get per-component marks positioned on
oh-yeah-fallback-formed LAM-ALEF ligatures with marks in between the LAM
and ALEF.

Now *that*'s pretty cool, if a bit anachronistic...

...with clusters spanning multiple base characters.