This change lets JavaPluginLoader use a temporary HashSet to store
methods that could possibly have the EventHandler annotation. Duplicates
are prevented by the nature of a Set.
Registering parent listeners is a breaking change for any listener
extending another listener and expecting parent listeners to not be
called. Changing this is justified by the ease-of-use and proper object
inheritance design. If this is undesired behavior, the method may be
overridden without reapplying the method with the EventHandler notation.
By: Wesley Wolfe <weswolf@aol.com>
29a5295348