GUI: preparation for custom error handling

 - Standard error widget can now be generated by method in UiElements.
 - Call URL and posted object can now be injected to PerunError and by this
   passed to custom handling in method onError(PerunError error) of callback.
- Modified JsonClient and JsonPostClient to reflect this error.
- Source formatting needed because of formatting change in sources.
GUI: custom error handling for AddMember call

 - Custom error handling for AddMember callback for
   AlreadyMemberException, WrongAttributeValueException
   and WrongReferenceAttributeValueException.
 - Fixed mistaken error.getType() for error.getName().
GUI: custom error handling for more calls

- Added custom error handling for calls AssignGroupToResources
  and AssignGroupsToResource.
- Fixed custom error texts.
CORE: added methods for listing direct rich admins with specific attributes

 - Added method getDirectRichAdminsWithSpecificAttributes() to VosManager,
   GroupsManager and FacilitiesManager.
- Added supportive method getDirectRichAdmins to Bl layer of same managers.
RPC: added new getAdmins() like method

- Added method getDirectRichAdminsWithSpecificAttributes() to
  VosManager, GroupsManager & FacilitiesManager.

- Added RPC javadoc above other getAdmins() like methods
GUI:  fixed listing of admins to show only direct on "users"

- Show only direct admins when listing users assigned as admins of entity.
- Modified texts on empty admins tables.
Merge pull request #235 from zlamalp/admins

CORE, RPC, GUI: added support for listing direct admins with attributes
Merge pull request #233 from zlamalp/exception

GUI: custom exception handling
GUI:  UX for facility administration

- Added filtering above TaskResults.
- Display type of destination as UpperCase.
- Inform, that "Services destinations" define, where service configuration
  is propagated. Show warning on delete hosts/destinations, informing
  about services propagations.
Core: fixed wrong exception in addServiceToPackage

- the method addServiceToServicesPackage now throws
  ServiceAlreadyAssignedException instead of InternalErrorException
  when the service is already assigned to the package
Core: fixed checkAttribute[s] for VOs

- now the checking of an attribute for VO runs only when the attribute is not null
  or is truly required (Task #1527)
Added right licence.
Merge pull request #241 from tauceti2/master

Added right licence.
GUI: improved adding facility destinations

- Updated dialog for adding services destinations.
  Suggest existing hosts when destination is HOST type.
  Check for valid email format when MAIL and SIGNED_MAIL
  destination format.
Merge pull request #242 from zlamalp/fac_setting

GUI: UX for facility administration
Merge pull request #238 from jirmauritz/servicePackages

Core: fixed wrong exception in addServiceToPackage
Merge pull request #237 from jirmauritz/checkAttribute

Core: fixed checkAttribute[s] for VOs
GUI: custom error message on AddServiceToServicesPackage

- Display custom message since same exception is used for
  assigning service to resource, which is not the case
  of AddServiceToServicesPackage.

- Source format of some classes.
Merge pull request #243 from zlamalp/assign

GUI: custom error message on AddServiceToServicesPackage
GUI: allow to use custom re-captcha public key

- Read public key for Re-Captcha from perun-web-gui.properties
  stored on server side. This will allow us to use it in
  different Perun instances without need to share are private
  key part.

- If key not present, stop loading appForm gui and display error message.

- Updated PerunError object, so more properties can be set manually.

- Small updates to error reporting widget.

- When response on POST is null (error case) and callback is hidden,
  do not show error report widget.