subcommand for displaying support crypt algorithms.


- Aliases
    - avoid looping aliases

- Domain
    - optional limits for number of:
        + accounts
        + aliases
        + destinations/alias
        + alias domains

Database:
   public.users.digestmd5: add "character varying(48)"
	Outlook will love it. (`doveadm pw -s DIGEST-MD5.hex -p 1 -u 0`)