VMM/Alias: renamed Alias.add_destination() to add_destinations(). Now it's possible to add one ore more destinations to the alias with a single method call. VMM/Handler: adjusted Handler.aliasAdd() to the API changes of the Alias class. Also use get_gid from the Domain module to get the gid of a domain. We don't need complete Domain object, only the gid. Handler.getWarnings(): no longer return the __warnings list. Return a copy instead and empty the Handler.__warnings list.

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