[YellowBike] good administrative changes to list

[Aaron Wieler]

ok. I've changed the list options so you can only post to the list if you're
a member. that's to protect us from spam. sometimes exciting people email us
to ask about starting communiy bike programs, etc, and this change will make
it harder for them to post (they'll have to subscribe or email me). but it
will save us from reading endless drug and sex advertisements.

anyone disagree?

happy snowbiking. unless there's no snow where you are.

yellowlove,
aaron