`--clear` is a design smell on the `azureauth aad` command.

[kyle-rader]

Having --clear take over and do something entirely different on that command, and not actually be tied to the specific client/scope pair is confusing. This would likely be better suited in it's own reset command that attempts to reset all state related to AzureAuth for more holistic troubleshooting and debugging.

[goagain]

#187 should do same thing!