pgsql: Add strlcat() from OpenBSD, to be used for replacing strncat and

Log Message:
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Add strlcat() from OpenBSD, to be used for replacing strncat and other
strange coding practices.

Modified Files:
--------------
pgsql:
configure (r1.533 -> r1.534)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/configure.diff?r1=1.533&r2=1.534)
configure.in (r1.500 -> r1.501)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/configure.in.diff?r1=1.500&r2=1.501)
pgsql/src/bin/pg_config:
pg_config.c (r1.23 -> r1.24)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_config/pg_config.c.diff?r1=1.23&r2=1.24)
pgsql/src/include:
pg_config.h.in (r1.110 -> r1.111)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/pg_config.h.in.diff?r1=1.110&r2=1.111)
port.h (r1.109 -> r1.110)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/port.h.diff?r1=1.109&r2=1.110)

Added Files:
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pgsql/src/port:
strlcat.c (r1.1)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/port/strlcat.c?rev=1.1&content-type=text/x-cvsweb-markup)