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

[Heidi Eckhart]

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