Improve the error reporting

[nbraud]

Continuation of #240. Currently, the error and warning logs can get pushed off the screen by the backtrace.

[nbraud]

@duckinator What would you think of logging the backtrace to a temporary file and giving a link to that (unless the user requests verbose errors via a CLI flag or an environment variable)

[duckinator]

@nbraud I'd be okay with that. Do you think we should tie it to --verbose, --debug, or something else?

(Sorry for the slow response, in the process of getting a new house.)

[nbraud]

@nbraud Do you think we should tie it to --verbose, --debug, or something else?

Yes, I think it would make sense not to display the backtrace (and only the exception itself) unless some flag is set, and unconditionally save it to a text file.

(Sorry for the slow response, in the process of getting a new house.)

I know, hon, and it's entirely fine. I've not been particularly responsive myself either in the last couple of months, and I'm not even moving ;3