Add methods for work with roles

  - create setRole(authorizedGroup / User, complementaryObjects)
  - create unsetRole(authorizedGroup / User, complementaryObjects)
  - create manageRole (set and unset roles for 1 comp object)
  - add new addAdminWithoutRefresh and removeAdminWithoutRefresh methods
  - add new methods addObserver, removeObserver (for work with
    VoObserver)
  - add methods setRole and unsetRole to RPC
  - add small tests of these methods
Please add notnull check for "complementaryObjects"