SAP CRM settype Key structure determination

For background of this issue, please read Implementation guide for Genil Model attributes set as Read-Only. Detail logic could be found in program LCOM_SETTYPE_GENF05:

For 00 - single line settype and 10 - multiple line settypes, they have different handler classes assigned.

The handling logic are different due to the fact that single line settype does not have key structure at all.