Use better exceptions in AttributesManager Entry

- instead of InternalErrorException use in getAttributes and fillAttributes methods (where attributes come from core)  ConsistencyErrorException
- instead of InternalErrorException user in setAttributes and removeAttributes methods (where attributes comes from GUI) WrongAttributeAssignmentException
Merge pull request #217 from stavamichal/fix_exceptions_in_attributes_manager_entry

Use better exceptions in AttributesManager Entry
Core: repaired facilitiesManager.getAllowedUsers

- the method now returns list of unique users
- the test for uniqueness written
- moddified assignService() in ResourceManager
- added check of facility attributes and resource attributes
Merge pull request #222 from jirmauritz/getAllowedUsers

Core: repaired facilitiesManager.getAllowedUsers
Merge pull request #140 from papperwing/AssignServiceAttrTest

Core: added checks of facility attributes and resource attributes in assignService() in ResourceManager
Fix of dependecies of UF:V:shell

Fix of typo in dependecies.

U:D:preferredShells wasn't in dependencies of UF:V:shell therefore if
U:D:preferredShells changed, core wasn't notified about possible change
of UF:V:shell.
Fix of typo in attributes description

Changes to be made in production instance:
Chnge description of U:D:preferredShells and UF:V:shell according to
corresponding modules.