[fUML] implement operations of ExpansionActivationGroup, add subset/union to references of ExpansionActivationGroup/ ActivityNodeActivationGroup
[fUML] implement operations of ExpansionActivationGroup, add subset/union to references of ExpansionActivationGroup/ ActivityNodeActivationGroup

MDE4CPP/MDE4CPP,MDE4CPP/MDE4CPP,MDE4CPP/MDE4CPP