Fix some newly modified tab-complete changes

Hi hackers,

I saw a problem when using tab-complete for "GRANT", "TABLES IN SCHEMA" should
be "ALL TABLES IN SCHEMA" in the following case.

postgres=# grant all on
ALL FUNCTIONS IN SCHEMA   DATABASE                  FUNCTION                  PARAMETER                 SCHEMA
         TABLESPACE 
ALL PROCEDURES IN SCHEMA  DOMAIN                    information_schema.       PROCEDURE                 SEQUENCE
         tbl 
ALL ROUTINES IN SCHEMA    FOREIGN DATA WRAPPER      LANGUAGE                  public.                   TABLE
         TYPE 
ALL SEQUENCES IN SCHEMA   FOREIGN SERVER            LARGE OBJECT              ROUTINE                   TABLES IN
SCHEMA

I found that it is related to the recent commit 790bf615dd, and maybe it's
better to fix it. I also noticed that some comments should be modified according
to this new syntax. Attach a patch to fix them.

Regards,
Shi yu