CR — Allow the possibility to define multiple standard events for an onPart

When visually modeling it is often desired to have a planItem react to multiple standard events (e.g. when a certain caseFileItem is created or update or addchild or removechild etc. do this).
Presently it is required to visually depict multiple copies of the caseFileItem with a separate onPart for each of the Standard events we want to react to because onPart can only have one standard event.
It is proposed to allow onPart to have multiple standard events defined all of them in a disjontion (e.g. created OR addchild OR removechild or etc.)