VMM/Account: Adjusted to changes in maillocation.MailLocation.
VMM/maillocation: Class MailLocation added missing property `mid`.
Added new error to VMM/constants/ERROR and doc/source/vmm_constants_error
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