CSPACE-3900 More support for invoking Batch processes. Refactored the invocation...

CSPACE-3900 More support for invoking Batch processes. Refactored the invocation slightly to support better error reporting, and to allow a given Batch job to handle various invocation modes. Extended the demo batch job to handle single and list invocation, and to actually create the LoanOut and the relations to the passed CSID(s). Added a series of tests to verify proper functioning and error handling for bad invocation, empty lists, etc. Fixed an odd exception in the ClientUtils, in which a URI cannot be cast to a String.