Subscribers should not assign a value to a channel
Subscribers should not assign a value to a channel

Previously, we allowed the first subscription to a channel to set its
initial value. Now, subscribers will create the channel but put it into
an uninitialized state -- any value is accepted for the initial subscription
and all subscribers will be woken when the channel is initialized by the
notifier.

sabretooth/enotify,sabretooth/enotify,sabretooth/enotify