Fix notify channels lifecycle for publisher

It's the channel that never changes so we might
as well keep a copy of it (even to consider closing
it when the publisher is closed as well).

Also add another little buffer.

Also add a very small buffer to the NotifyReturn channel
in case no one is listening on the other side.

I event thought about actually having a timeout when sending
to that channel, but it felt it could lead to loss of
events on non problematic situations, so let's see how this
works instead.

We were probably missing those updates after a
reconnection happens, since we stayed subscribed
to the previous channel notifications instead.

The channel takes ownership of those channels when
we call Notify*, so we should not be closing them
or a panic could happen due to double closure or
sending to a closed channel.

Make the property AutoAcknowledge available to be changed, and added function to stop consumers.

fix startNotifyFlowHandler (issue #13)

add connection options and stop publish

Adds the consume shutdown method

Adding support for publishing messages with an expiration.

declare exchange before binding

publish: message headers added

- Added WithPublishOptionsExpiration which permits message expiry when the TTL has been reached
- Introduced new message var to permit the confidiontal injection of amp.Publishing options in the future.

Replace logger with a Logger interface to allow for custom loggers.

variadic function options

trigger