New PCRE API proposal

[Petr Pisar]

Many of you use regular expressions. Many of the expression are more
than regular. They can be called Perl-Compatible Regular Expressions
(PCRE). Those who need to support PCRE in their code use usually the
well-known PCRE library <http://www.pcre.org/>.

PCRE library maintainers decided to design shiny new API and implement
it in a new PCRE2 library. (Don't panic, current PCRE library will be
_maintained_ for reasonable long time). This new API proposal is
available at
<ftp://ftp.csx.cam.ac.uk/pub/software/programming/pcre/Testing/PCRE2_proposal.pdf>.

Some of the new features are call-back based interface with thread-safe
memory model, proper (Unicode) code unit support (different character
widths), or start-pointer-and-length string specification.

Feel free to discuss these changes at PCRE development mailing list
<pcre-dev at exim.org>.

-- Petr