pgsql: Add: > * Consider sorting hash buckets so entries can be found

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

* Consider sorting hash buckets so entries can be found using a binary
search, rather than a linear scan
* In hash indexes, consider storing the hash value with or instead
of the key itself

Modified Files:
--------------
pgsql/doc:
TODO (r1.1536 -> r1.1537)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/TODO.diff?r1=1.1536&r2=1.1537)
pgsql/doc/src/FAQ:
TODO.html (r1.43 -> r1.44)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/FAQ/TODO.html.diff?r1=1.43&r2=1.44)