Generalized SCTP event handling.
Generalized SCTP event handling.

Now also works with kernel SCTP implementations.

Refactored io_readable some to avoid copying code shared by both kinds
of SCTP implementation. That refactor uncovered it needs some more
refactoring still, due to already duplicated code.

NEAT-project/neat,NEAT-project/neat,NEAT-project/neat,NEAT-project/neat,NEAT-project/neat