To allow reading of protocol states from other protocols or completely
different routines, we have to export these states to data structures
not requiring to lock the protocol loops.
On one hand, this doesn't give the reader the actual state "right now",
on the other hand, getting that is impossible in a properly
multithreaded environment and you will always get the information with
some (little but noteworthy) delay.
This implementation handles only the basic state information of the
protocols, common for all the protocols. Adding protocol-specific state
information should be done by implementing the protocol hook init_state().
Channel information is stored but not announced, as we don't need the
announcements for now.
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