Develop a notification API

[Kaffeine]

We need a message lossless way to mute a channel

[detrout]

Oh, this is so the separate notification listener stops bugging the user in addition to the text client?

Don't we also want a way of selectively disabling logging while allowing notifications and text ui? (useful for encrypted messages),

[Kaffeine]

Well, there is a solution that partially solves the issue: add "silent" message header key.
Connection Manager can set this key for messages based on notification settings. E.g. CM can mark all messages as 'silent' expect the ones with the local user mentioned.
Take a note that Telegram has a "silent" message flag too.

We still need some API to customize notification settings, but the flag will help in a lot of cases.