Add devel/oniguruma.

Oniguruma is a BSDL Regular Expression library written for ruby-m17n,
which implements all of Perl extensions plus more. It has multiple
APIs; GNU regex, POSIX regex and its own interface.

This library is fundamentally multilingualized and can have one
encoding for each object. Currently supported character encodings
are ASCII, UTF-8, EUC-JP and Shift_JIS.

Author: K.Kosako <kosako@sofnec.co.jp>
WWW: http://www.ruby-lang.org/cgi-bin/cvsweb.cgi/oniguruma/