New method getAttributes(sess, group, attrNames)
 - Added new method getAttributes into AttributesManagerEntry
 - Added new method getAttributes into AttributesManagerBl
 - Added new method getAttributes into AttributesManagerImpl
New bean RichGroup
 - Added RichGroup into beans
 - RichGroup extends Group
Core: New workflow for RichGroup
 - added method getAllRichGroupsWithAttributesByNames(PerunSession sess, Vo vo, List<String> attrNames) into GroupsManager
 - added method getRichSubGroupsWithAttributesByNames(PerunSession sess, Group parentGroup, List<String> attrNames) into GroupsManager
 - added method getRichGroupByIdWithAttributesByNames(PerunSession sess, int groupId, List<String> attrNames) into GroupsManager
 - added method convertGroupsToRichGroupsWithAttributes(PerunSession sess, List<Group> groups, List<String> attrNames) into GroupsManagerBl
 - added method convertGroupsToRichGroupsWithAttributes(PerunSession sess, List<Group> groups) into GroupsManagerBl
 - added method convertGroupToRichGroupWithAttributesByName(PerunSession sess, Group group, List<String> attrNames) into GroupsManagerBl
 - added method convertGroupToRichGroupWithAttributes(PerunSession sess, Group group) into GroupsManagerBl
Rich Group implementation

- add RichGroup to auditParser & to tests
- authorization added for methods getAllRichGroupsWithAttributesByNames,
getRichSubGroupsWithAttributesByNames,
getRichGroupByIdWithAttributesByNames
- added filters for richGroup attributes (filter only allowed attributes)
- javadoc
Merge pull request #417 from Natrezim/workBranch2

RichGroup Implementation