- Added the capability to specify a .draftboxes files, which lets the
  user associate an account with a dratbox folder on disk. If no
  .draftboxes file is found, midnight falls back to grepping around the
  neomutt config dir, looking for the 'postponed' configuration option.
- Disabled at(1) sending email to local mail spool on job success. Jobs
  that fail will still send an email to the local mail spool, though.
- Replaced local quirk with external quirks crate.