pgsql: Provide for binary input/output of enums, to fix complaint from

Log Message:
-----------
Provide for binary input/output of enums, to fix complaint from Merlin Moncure.
This just provides text values, we're not exposing the underlying Oid representation.
Catalog version bumped.

Modified Files:
--------------
    pgsql/src/backend/commands:
        typecmds.c (r1.106 -> r1.107)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/commands/typecmds.c?r1=1.106&r2=1.107)
    pgsql/src/backend/utils/adt:
        enum.c (r1.3 -> r1.4)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/adt/enum.c?r1=1.3&r2=1.4)
    pgsql/src/include/catalog:
        catversion.h (r1.421 -> r1.422)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h?r1=1.421&r2=1.422)
        pg_proc.h (r1.467 -> r1.468)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_proc.h?r1=1.467&r2=1.468)
    pgsql/src/include/utils:
        builtins.h (r1.301 -> r1.302)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/include/utils/builtins.h?r1=1.301&r2=1.302)