pgsql: Don't treat NEW and OLD as reserved words anymore.

Log Message:
-----------
Don't treat NEW and OLD as reserved words anymore.  For the purposes of rules
it works just as well to have them be ordinary identifiers, and this gets rid
of a number of ugly special cases.  Plus we aren't interfering with non-rule
usage of these names.

catversion bump because the names change internally in stored rules.

Modified Files:
--------------
    pgsql/doc/src/sgml:
        keywords.sgml (r2.26 -> r2.27)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/keywords.sgml?r1=2.26&r2=2.27)
        rules.sgml (r1.52 -> r1.53)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/rules.sgml?r1=1.52&r2=1.53)
        syntax.sgml (r1.137 -> r1.138)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/syntax.sgml?r1=1.137&r2=1.138)
    pgsql/src/backend/commands:
        view.c (r1.118 -> r1.119)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/view.c?r1=1.118&r2=1.119)
    pgsql/src/backend/parser:
        gram.y (r2.687 -> r2.688)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/gram.y?r1=2.687&r2=2.688)
        parse_utilcmd.c (r2.28 -> r2.29)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/parser/parse_utilcmd.c?r1=2.28&r2=2.29)
    pgsql/src/backend/rewrite:
        rewriteDefine.c (r1.138 -> r1.139)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/rewrite/rewriteDefine.c?r1=1.138&r2=1.139)
        rewriteHandler.c (r1.191 -> r1.192)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/rewrite/rewriteHandler.c?r1=1.191&r2=1.192)
        rewriteManip.c (r1.124 -> r1.125)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/rewrite/rewriteManip.c?r1=1.124&r2=1.125)
    pgsql/src/backend/utils/adt:
        ruleutils.c (r1.313 -> r1.314)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/ruleutils.c?r1=1.313&r2=1.314)
    pgsql/src/include/catalog:
        catversion.h (r1.549 -> r1.550)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h?r1=1.549&r2=1.550)
    pgsql/src/include/parser:
        gramparse.h (r1.48 -> r1.49)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/parser/gramparse.h?r1=1.48&r2=1.49)
        kwlist.h (r1.5 -> r1.6)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/parser/kwlist.h?r1=1.5&r2=1.6)
    pgsql/src/interfaces/ecpg/preproc:
        ecpg.addons (r1.5 -> r1.6)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/preproc/ecpg.addons?r1=1.5&r2=1.6)
        ecpg.header (r1.9 -> r1.10)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/preproc/ecpg.header?r1=1.9&r2=1.10)
        ecpg.trailer (r1.12 -> r1.13)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/preproc/ecpg.trailer?r1=1.12&r2=1.13)
        ecpg.type (r1.1 -> r1.2)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/preproc/ecpg.type?r1=1.1&r2=1.2)
        parse.pl (r1.3 -> r1.4)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/ecpg/preproc/parse.pl?r1=1.3&r2=1.4)