Followers can now be partners or channels. Partners following a document
will receive needaction, as previously. However people can follow documents
through channels. Members of a channel are able to listen to a stream
of messages using the channel. Those messages do not create needaction
messages. It is therefore possible to follow documents without receiving
too much notifications. For interesting documents subscribing with its
partner will create notification.
message_follower_ids fields is udpated. It is now a many2many to
mail.followers, not to res.partner anymore. A subscription can be either
a partner (partner_id) or a channel (channel_id).
Some access rules have been updated accordingly.
Thibault Delavallée
e6f038a821