pgsql: Add: > > o Allow pg_hba.conf to specify host names along with

Log Message:
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Add:

o Allow pg_hba.conf to specify host names along with IP addresses

Host name lookup could occur when the postmaster reads the
pg_hba.conf file, or when the backend starts. Another
solution would be to reverse lookup the connection IP and
check that hostname against the host names in pg_hba.conf.
We could also then check that the host name maps to the IP
address.

Modified Files:
--------------
pgsql/doc:
TODO (r1.1767 -> r1.1768)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/TODO.diff?r1=1.1767&r2=1.1768)
pgsql/doc/src/FAQ:
TODO.html (r1.272 -> r1.273)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/FAQ/TODO.html.diff?r1=1.272&r2=1.273)