VMM/{Account,common,maillocation}: Dovecot version (check) fixes.
    - Account: fixed versions dependencies.
    - maillocation: use the version string, may be uses in a error message.
    - common: version_hex() raises a ValueError, instead of returning 0,
      if the version string is invalid.
Config
   cfs - configset sect.opt val
   cfg - configget sect.opt
   ds - domainservices: smtp pop imap sieve???
- Aliases
    - avoid looping aliases
- Domain
    - optional limits for number of:
        + accounts
        + aliases
        + destinations/alias
        + alias domains
Database:
   public.users.passwd: increase to "character varying(150)"
   	why? `doveadm pw -s SSHA512.hex -p 1`
   public.users.digestmd5: add "character varying(48)"
	Outlook will love it. (`doveadm pw -s DIGEST-MD5.hex -p 1 -u 0`)