Informative error printout on closing

[draelos]

When improv closes (the TUI disappears), it exists cleanly. It would be good to add a feature where any errors/exceptions that precipitated the closing were then printed out to the command line interface (stdout) to highlight them.
We would use it for an actor dying during setup (and thus improv closes), or improv itself has an error, or anything that resulted in a dirty cleanup. Improv should print the exception traceback if possible, and include a note to look in global.log for the complete log associated with the error.
We should also advise users to run improv list and, if necessary, improv cleanup in those cases as well.

[draelos]

One additional note: this could also include expanding some of our current error messages to be more informative than 'see the log file' (e.g. here); even just 'see global.log' would be better.

[jmxpearson]

Even better if we can make sure we’re re-raising exceptions. If they’re caught by the CLI, we can actually print the error message using the log file name specified at the command line (which need not be global.log.

[jmxpearson]

@draelos, I think we can close this one now?