- add (optional) timeout for wait_for_hidden_host

- add ability for modules to register additional sockets to monitor
  (and socket_listener example module)
  also FDs so the bot can monitor a pipe
  - add a pipe which allows to input commands even when IRC connection is gone
    this might be difficult since there won't be a bot or user or chan object...

- implement timers in the core and/or modlib, by adjusting the select timeout whenever a timer is pending.
  call timers as part of the event loop.
  this has the potential to remove a LOT of the threading.