[Papyon] keepalive switchboards

[Riccardo (C10uD)]

Today i tried to do some work towards implementing keepalives for switchboards.

See [1] and [2]

Some comments:
I'm unsure on how to check if a switchboard is dedicated to p2p so we
avoid keeping them opened.
The self.__keepalive_conversations = True is for testing purposes only.
Also i'm unsure if we need type 'A' or 'N' for keepalive messages
acknowledgement type. I set 'N' but in emesene1 we had 'A'. I guess
'N' should be enough here?

Other than that please try it and give feedback

greets
Riccardo
___
[1] https://github.com/emesene/papyon/commit/f2c1b1af3902d05aa330e205e53c194d90413a25
[2] https://github.com/emesene/papyon/commit/231ede95507a9826469ae45619ffc45b6f42ba1d