This is a follow-on in that the old utf8 code was still being
used in ncgen to convert utf8->utf16 when converting cdl to Java
(see genj.c).
The new code apparently has no utf16 support, but it does have
utf32 support. Converting utf32 -> utf16 can be approximated by
truncating the 32bits to 16 bits, unless the top 16 bits are
not zero. This latter condition is unlikely to be common because
it implies use of some rather obscure characters.
So solution is to convert to utf32 and truncate to 16 bits to
get utf16. An error is reported if the high-order truncated 16
bits are not zero. If we get complaints, then I will figure out
how to convert full utf32 to a utf16 pair.
Also removed the old code from ncgen.
Update utf8proc.[ch] to use the version now
maintained by the Julia Language project
(https://github.com/JuliaLang/utf8proc/blob/master/LICENSE.md).
The license for the previous version was
unacceptable for the Debian and Ubuntu release
systems. The new version both updates the code
and addresses the license issue.
It turns out that the utf8proc software we are using
was turned over to the Julia Language developers
and the license terms changed to allow modification.
(https://github.com/JuliaLang/utf8proc/blob/master/LICENSE.md).
So the fix here is as follows:
1. Wrap the library with a fixed interface: libdispatch/dutf8.c
and include/ncutf8.h.
2. Replace the existing utf8proc code with the new version
from https://github.com/JuliaLang/utf8proc.
3. Add a couple more test cases: nc_test/tst_utf8_validate.c
and nc_test_utf8_phrases.c. If/when I can find a usable
normalization test, I will incorporate that later.
