Set default empty array value on API/../Limitation->limitationValues
Implement LimitationType validation

Reusing the validationError from FiledType
Todo:
- Move ValidationError it out of field type
- Find a better exception for validation error ala ContentFieldValidation

Warning: This commit breaks tests, some tests are using invalid values.
Fix Unit-/Integration-Tests for limitations validation

Includes:
- IntegrationTest: Wrong usage of module/function for state limitation
- UnitTest: Issues with order of policies from persistence
- UnitTest: RoleServiceTest invalid limitation use
- IntegrationTest: RoleServiceTest invalid limitation use
Add full UnitTests coverage for some LimitationTypes
Merge pull request #292 from ezsystems/limitation_validation

Fix EZP-20102: Limitation Types are not validated by Public API Policy create/update methods