Feature request: Don't call if group size is 0

[jeffchan]

group.now.distribute(msg);

throws a reference error when group size is zero, which leads to this rather annoying fix:

group.count(function(num) {
    if (num > 0) {
        group.now.distribute(msg);
    }
});

I propose that the RPCs simply get skipped if group size is 0.

[steveWang]

I can't reproduce this.