Fix error message for visit attribute types - TRUNK-3230
UserContext should store locationId instead of the Location object - TRUNK-3883

added some changes

applying auto commit changes

Fixed userContext.getLocation to return null when locationId is null -
TRUNK-3883

Added @since and javadocs for getters and setters of
userContext.locationId - TRUNK-3883
Resolving conflicts
Add SerializableComplexObsHandler interface for form processing methods 
- TRUNK-3886