pgsql: Add the usage count statistics to the information available in

Log Message:
-----------
Add the usage count statistics to the information available in
contrib/pgbuffercache.

Greg Smith

Modified Files:
--------------
pgsql/contrib/pg_buffercache:
README.pg_buffercache (r1.3 -> r1.4)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/pg_buffercache/README.pg_buffercache.diff?r1=1.3&r2=1.4)
pg_buffercache.sql.in (r1.4 -> r1.5)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/pg_buffercache/pg_buffercache.sql.in.diff?r1=1.4&r2=1.5)
pg_buffercache_pages.c (r1.11 -> r1.12)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/pg_buffercache/pg_buffercache_pages.c.diff?r1=1.11&r2=1.12)