pgsql: Use pg_get_triggerdef in pg_dump Add a variant of

Log Message:
-----------
Use pg_get_triggerdef in pg_dump

Add a variant of pg_get_triggerdef with a second argument "pretty" that
causes the output to be formatted in the way pg_dump used to do.  Use this
variant in pg_dump with server versions >= 8.5.

This insulates pg_dump from most future trigger feature additions, such as
the upcoming column triggers patch.

Author: Itagaki Takahiro <itagaki.takahiro@oss.ntt.co.jp>

Modified Files:
--------------
    pgsql/doc/src/sgml:
        func.sgml (r1.487 -> r1.488)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/func.sgml?r1=1.487&r2=1.488)
    pgsql/src/backend/utils/adt:
        ruleutils.c (r1.307 -> r1.308)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/ruleutils.c?r1=1.307&r2=1.308)
    pgsql/src/bin/pg_dump:
        pg_dump.c (r1.549 -> r1.550)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_dump.c?r1=1.549&r2=1.550)
        pg_dump.h (r1.158 -> r1.159)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/pg_dump/pg_dump.h?r1=1.158&r2=1.159)
    pgsql/src/include/catalog:
        catversion.h (r1.543 -> r1.544)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h?r1=1.543&r2=1.544)
        pg_proc.h (r1.551 -> r1.552)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_proc.h?r1=1.551&r2=1.552)
    pgsql/src/include/utils:
        builtins.h (r1.339 -> r1.340)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/builtins.h?r1=1.339&r2=1.340)