Changed Subscription Mode (for Strong/Weak references) to be it's own class

src/dorkbox/messageBus/SubscriptionMode.java

@@ -0,0 +1,23 @@
+package dorkbox.messageBus;
+
+/**
+ *
+ */
+public
+enum SubscriptionMode {
+    /**
+     * This is the default.
+     * <p>
+     * We use strong references when saving the subscribed listeners (these are the classes & methods that receive messages).
+     * <p>
+     * In certain environments (ie: spring), it is desirable to use weak references -- so that there are no memory leaks during
+     * the container lifecycle (or, more specifically, so one doesn't have to manually manage the memory).
+     */
+    StrongReferences,
+
+    /**
+     * Using weak references is a tad slower than using strong references, since there are additional steps taken when there are orphaned
+     * references (when GC occurs) that have to be cleaned up. This cleanup occurs during message publication.
+     */
+    WeakReferences
+}

src/dorkbox/messageBus/annotations/Listener.java

@@ -45,12 +45,11 @@ import java.lang.annotation.Target;
 public
 @interface Listener {
     /**
-     * By default, references to message listeners (these are the objects/methods that receive messages) are strong. This default can be
-     * changed via a static boolean (during startup, see MessageBus.useStrongReferencesByDefault).
+     * By default, references to message listeners (these are the objects/methods that receive messages) are strong. See {@link dorkbox.messageBus.SubscriptionMode}).
      *
      * The benefits to use WEAK references, is to eliminate risks of memory leaks in managed environments (such as spring).
      *
-     * the default here "Undefined" here so that the static boolean (MessageBus.useStrongReferencesByDefault) takes priority
+     * the default here "Undefined" here so that the {@link dorkbox.messageBus.SubscriptionMode#StrongReferences} takes priority
      */
     References references() default References.Undefined;
 }