Description:

Refactored lib/imapoptions for easier maintenance and extensibility


Documentation:

lib/imapoptions/README.md


Config changes:

(all, or none, depending on how you think about it)


Upgrade instructions:

Need perl modules "Moo" and "App::Cmd".  In apt, these are libmoo-perl
and libapp-cmd-perl.


GitHub issue:

None
