pgsql: Update text: < * Prevent long-lived temporary tables from

Log Message:
-----------
Update text:

< * Prevent long-lived temporary tables from causing frozen-Xid advancement
> * Prevent long-lived temporary tables from causing frozen-xid advancement
>
>    The problem is that autovacuum cannot vacuum them to set frozen xids;
>    only the session that created them can do that.
>
>
>

Modified Files:
--------------
    pgsql/doc:
        TODO (r1.2225 -> r1.2226)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/TODO?r1=1.2225&r2=1.2226)
    pgsql/doc/src/FAQ:
        TODO.html (r1.734 -> r1.735)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/FAQ/TODO.html?r1=1.734&r2=1.735)