[TRUNK-4095] Fix Validators to compare by uuid when checking for duplicates
[TRUNK-4095] replaced conceptToValidate.getConceptId() != null with conceptToValidate.getUuid() != null
[TRUNK-4095] made some changes and aand also fixed in ConceptReferenceTermValidator.java and PersonAttributeTypeValidator.java
Merge pull request #404 from k-joseph/TRUNK-4095

TRUNK-4095