[AltEnum] Added AltEnum project for experiments with alternatives to enum
[Messaging] Merge branch 'AltEnum' into Messaging
[Messaging] Renamed Socket::socket_type to Socket::Type
[Messaging] Refactored Poller::Events to use const expressions
[Messaging] Devised alternate representation of Events to avoid statics
[Messaging] Refactored Poller::Events to use std::set
[Messaging] Amended Poller::dispatch to take a copy of the sockets list before iterating, in case the functor modifies it
[Messaging] Added Poller::Event tests