pgsql: Make autovacuum behavior more agressive, per discussion on - Mailing list pgsql-committers

Log Message:
-----------
Make autovacuum behavior more agressive, per discussion on hackers list
--- was part of autovacuum default 'on' patch that was reverted, but we
want this part.

Peter Eisentraut

Modified Files:
--------------
    pgsql/doc/src/sgml:
        config.sgml (r1.81 -> r1.82)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/config.sgml.diff?r1=1.81&r2=1.82)
    pgsql/src/backend/utils/misc:
        guc.c (r1.349 -> r1.350)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/guc.c.diff?r1=1.349&r2=1.350)
        postgresql.conf.sample (r1.190 -> r1.191)

(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/postgresql.conf.sample.diff?r1=1.190&r2=1.191)