pgsql: Add three new regexp functions: regexp_matches,

Log Message:
-----------
Add three new regexp functions: regexp_matches, regexp_split_to_array,
and regexp_split_to_table. These functions provide access to the
capture groups resulting from a POSIX regular expression match,
and provide the ability to split a string on a POSIX regular
expression, respectively. Patch from Jeremy Drake; code review by
Neil Conway, additional comments and suggestions from Tom and
Peter E.

This patch bumps the catversion, adds some regression tests,
and updates the docs.

Modified Files:
--------------
    pgsql/doc/src/sgml:
        func.sgml (r1.369 -> r1.370)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/func.sgml.diff?r1=1.369&r2=1.370)
    pgsql/src/backend/utils/adt:
        regexp.c (r1.69 -> r1.70)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/regexp.c.diff?r1=1.69&r2=1.70)
    pgsql/src/include/catalog:
        catversion.h (r1.392 -> r1.393)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h.diff?r1=1.392&r2=1.393)
        pg_proc.h (r1.448 -> r1.449)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_proc.h.diff?r1=1.448&r2=1.449)
    pgsql/src/include/utils:
        builtins.h (r1.289 -> r1.290)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/builtins.h.diff?r1=1.289&r2=1.290)
    pgsql/src/test/regress/expected:
        strings.out (r1.29 -> r1.30)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/strings.out.diff?r1=1.29&r2=1.30)
    pgsql/src/test/regress/sql:
        strings.sql (r1.18 -> r1.19)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/strings.sql.diff?r1=1.18&r2=1.19)