Fix output of ObjectId("...").toString()

Signed-off-by: Sam Kleinman <samk@10gen.com>
manage-sharded-cluster.txt: Clarify stopping the balancer

Strictly speaking, the statement after "sh.setBalancerState(false)" is correct.  However it is extremely misleading, because it implies that the setBalancerState command will wait for any current balancing round to finish, which is not true.  The "sh.stopBalancer()" helper is the safest way to disable the balancer.

Signed-off-by: Sam Kleinman <samk@10gen.com>
Adjust URL for repo to use https:// over git://

HTTPS is GitHub's recommended clone method for security.

Signed-off-by: Sam Kleinman <samk@10gen.com>