Merge branch '235-transport-key-manager-deadlock' into 'master'

Avoid potential deadlock in TransportKeyManager. #235

See rambling description on the ticket and in the architecture channel...

Fixes #235.

See merge request !79

briar-api/src/org/briarproject/api/event/EventListener.java

@@ -3,5 +3,9 @@ package org.briarproject.api.event;
 /** An interface for receiving notifications when events occur. */
 public interface EventListener {
 
+	/**
+	 * Called when an event is broadcast. Implementations of this method must
+	 * not block.
+	 */
 	void eventOccurred(Event e);
 }