Add description:

Add description:

< 	  This would require a new global table that is dumped to flat file for
< 	  use by the postmaster.  We do a similar thing for pg_shadow currently.
> 	  This would add a function to load the SQL table from
>           pg_hba.conf, and one to writes its contents to the flat file.
> 	  The table should have a line number that is a float so rows
> 	  can be inserted between existing rows, e.g. row 2.5 goes
> 	  between row 2 and row 3.