Implement new automatic subscriptions in proposal related resource spaces

[cdparra]

-- [AppCivist] Auto subscriptions:
-- proposal creator (test)
-- proposal share-with (test)
-- auto subscription for proposal once it is made public or published: WG member (implement)
-- we first subscribe them
-- then we notify all subscribers that a new proposal has been made public or published
-- script to create subscriptions for current WGs members on their WGs current public/published proposals