pgsql: Rename the recently-added pg_timezonenames view to

Log Message:
-----------
Rename the recently-added pg_timezonenames view to pg_timezone_abbrevs,
and create a new view pg_timezone_names that provides information about
the zones known in the 'zic' database.  Magnus Hagander, with some
additional work by Tom Lane.

Modified Files:
--------------
    pgsql/doc/src/sgml:
        catalogs.sgml (r2.131 -> r2.132)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/catalogs.sgml.diff?r1=2.131&r2=2.132)
    pgsql/src/backend/catalog:
        system_views.sql (r1.30 -> r1.31)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/catalog/system_views.sql.diff?r1=1.30&r2=1.31)
    pgsql/src/backend/utils/adt:
        datetime.c (r1.170 -> r1.171)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/datetime.c.diff?r1=1.170&r2=1.171)
    pgsql/src/include/catalog:
        catversion.h (r1.356 -> r1.357)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h.diff?r1=1.356&r2=1.357)
        pg_proc.h (r1.424 -> r1.425)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_proc.h.diff?r1=1.424&r2=1.425)
    pgsql/src/include:
        pgtime.h (r1.12 -> r1.13)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/pgtime.h.diff?r1=1.12&r2=1.13)
    pgsql/src/include/utils:
        datetime.h (r1.60 -> r1.61)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/datetime.h.diff?r1=1.60&r2=1.61)
    pgsql/src/test/regress/expected:
        rules.out (r1.118 -> r1.119)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/rules.out.diff?r1=1.118&r2=1.119)
    pgsql/src/timezone:
        pgtz.c (r1.44 -> r1.45)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/timezone/pgtz.c.diff?r1=1.44&r2=1.45)