add method to get all Session IDs from SessionSettings object

This might already be possible, but I cannot find the method; being new, i obviously am learning a lot.

Consider adding a method with the following signature to SessionSettings

public void List getSessionIds()

This would return a non-null implementation of List, probably an ArrayList. I would not expect this method to throw an error. The SessionID object is immutable, i.e. there are no setXXX() methods, so I do not think that there ought to be an issue with returning the keys to the underlining hash.... though I could be wrong.

Such a method would seem to make sense since most of the other methods in SessionSettings take a SessionID parameter.