users should be able to diagnose issues with sending IRC messages

[flavorjones]

A few potential problem that users have no insight into:

• debug info
  • what the resource is doing on the IRC-level (for this Elemental-IRCd/irc has a property irc.Debug we can set)
  • what the resource is doing on the business-logic level (ordinary debug trace)
• diagnostic info
  • if any of the socket writes fail, the resource isn't checking the irc error channel so we won't know
  • if the IRC server responds with an error message (e.g. "you're not privileged"), the resource isn't looking at the events generated by irc.readLoop()

I've created this issue to address these shortcomings.

[flavorjones]

Debug trace was added in f90434b