pgsql: IBM has addressed the socket address storage issue as of AIX 5.3

Log Message:
-----------
IBM has addressed the socket address storage issue as of AIX 5.3
maintenance level 5300-03; the following patch adds documentation to
FAQ_AIX.

Chris Browne

Modified Files:
--------------
pgsql/doc:
FAQ_AIX (r1.12 -> r1.13)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/FAQ_AIX.diff?r1=1.12&r2=1.13)