Remove unused code
* Fix silent swallowing of exception when it's not one of the 2 planned cases
* When we parse a "known" exception, shorten the nesting stack
In ERROR log, ALWAYS print the error message, and print print a nesting summary (shorter now)
Reorder
Add a variant of Command.error which adds specific handling of some "well-known" exceptions, to present nicer messages to the user
Handle another type of error
* When we parse a clean exception, don't rethrow it as a generic one, use a specific exception for auth failed
* Don't write "Unknown exception", it brings no additional information, and is frightening
Move files to their correct location, fix excessive line length and hard-to-read indentation