[Libvirt-cim] [PATCH 0 of 3] #4 - Enhance std association logic for reference lists and input parameter handling

This patch set fixes: - enhance the std_assoc struct to support lists for source, target and association classnames - fixed a wrong error return for a NULL handler - reworked check for input parameter: assocClass, resultClass, role, resultRole Diff to patch set #3: - fixed patch 3 of 3: std_assoc_get_handler did not set handler to NULL in case of "no valid handler found" and so returned wrong handler