Need a way to prevent replying to itself

[joaocac]

Example:

• An API listener is set to reply a message every time it senses a signal
• As it sends a signal back, it will also sense it, so we have a loop generation or replying to its own replies

Possible solution:

• Add a sender hash (API object based) to the message
• Mark with a hash the listener (API object based)
• If the listener to be called have the same hash of the message sender, then it will be skipped

[joaocac]

We do have a mechanism of adding a reply flag to the reply message. But the problem persists since we can have two listeners that expect replies.

We could have the reply flag to have a message id, representing the message that we are replying to.
This could be a possible and meaningful solution since we have the message ID when we send it.

[joaocac]

• Adding a sender hash seems to be the best approach to disregard self-messages.
• Having a mechanism to temporarily create a channel so we can expect a reply to a specific message should be possible by the method sendAndListen. the generated channel will die after the reply releasing resources.
• There should exist little or no other mechanism since this is a signaling system where any interested party should be able to listen.

[joaocac]

Requires: #22
Waiting for #22 to be finished