refactored XMLSchemaService to not have static methods. made the CrudServiceTest more robust.
removed CrudService dependency on servlet params. CrudService is now a singleton. I'm getting an error from metacat saying it can't find teh systemmetadata schema, even though it is, in fact, registered with metacat. need to identify why this is happening.
added a test for CrudService and added tests for IdentifierManager for each method