If addMemberList is called on CompositeList as part of a list event response,
the change to the CompositeList is dropped.
Demonstrating this issue involves a fairly complex list pipeline. I've prepared
a unit test that demonstrates the issue.
As near as I can tell, the dropped event occurs because of two things in
1. the loop that checks for subjects (the first for loop in the method) does
not find any entries for the addMemberList event (maybe a listener isn't getting
2. reentrantFireEventCount is equal to 2 during the addMemberList event
handler, so processing delegates to the stack (but because of #1, nothing gets
added for the stack to handle)