Reference class members via class, not instance. As its just read access, no copies as instance members might be created, but just make sure, and be clear here.
Moved syslog message formatting out of the class into a function. Use generator.
Simplified IRC server argument parsing, extracted it into a function, and added tests for it.
Extracted parts of the IRC server argument parsing into a factory. Use `split()` instead of `partition()` to get a dynamic number of fragments (here: one or two).
Dropped custom `HostAndName` tuple in favor of the IRC lib's `ServerSpec` value entity. Fetch default IRC port from there.
Based tests on the `unittest` module and (necessarily) its test case class approach to be able to use its assertion matchers which provide way better output.
Bumped version date.