pgsql: Add: > * Improve deadlock detection when deleting items from

Log Message:
-----------
Add:

* Improve deadlock detection when deleting items from shared buffers

http://archives.postgresql.org/pgsql-bugs/2008-01/msg00138.php
http://archives.postgresql.org/pgsql-hackers/2008-01/msg00873.php
http://archives.postgresql.org/pgsql-committers/2008-01/msg00365.php

Modified Files:
--------------
pgsql/doc:
TODO (r1.2242 -> r1.2243)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/TODO?r1=1.2242&r2=1.2243)
pgsql/doc/src/FAQ:
TODO.html (r1.751 -> r1.752)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/FAQ/TODO.html?r1=1.751&r2=1.752)