pgsql: Remove contrib version of pg_autovacuum --- superseded by

Log Message:
-----------
Remove contrib version of pg_autovacuum --- superseded by integrated
version.

Modified Files:
--------------
    pgsql/contrib:
        Makefile (r1.59 -> r1.60)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/Makefile.diff?r1=1.59&r2=1.60)
        README (r1.81 -> r1.82)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/README.diff?r1=1.81&r2=1.82)

Removed Files:
-------------
    pgsql/contrib/pg_autovacuum:
        Makefile
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/pg_autovacuum/Makefile)
        README.pg_autovacuum
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/pg_autovacuum/README.pg_autovacuum)
        TODO
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/pg_autovacuum/TODO)
        pg_autovacuum.c
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/pg_autovacuum/pg_autovacuum.c)
        pg_autovacuum.h
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/pg_autovacuum/pg_autovacuum.h)