TODO In SILC Libraries
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+ o Rewrite the task system. I made it too complex and too "neat" and
+ it really should be rewritten. We don't need priorities really, one
+ priority is enough. This will simplify a lot the task system.
+
o Implement PFS (Perfect Forward Secrecy) flag in SKE (and in client and
server, actually). If PFS is set, re-key must cause new key exchange.
This is required by the SILC protocol.