Emit raise event.

Just before the error event is emitted, this allows programs to collect
errors or log them whilst letting the default error handling apply.
0.8.187
Update cli-error.
0.8.188
Update logger prefix handling.
0.8.189
Improve log prefix default handling.
0.8.190
Debug log prefix formatting issue.
0.8.191
Assign persistent reference to rc data.
0.8.192
Fix bug with top-level custom help sections.
0.8.193
Allow env to be cached.
0.8.194
Fix issue with command required callback.
0.8.195
Expose complete method to req.

So that code may explicitly finish and ensure either the callback is
invoked or the complete event is emitted.

Useful for interactive programs that have more complex flow control
requirements.
0.8.196