Print stack trace for uncaught exceptions during tests for easier debugging

briar-tests/src/org/briarproject/BriarTestCase.java

@@ -10,6 +10,7 @@ public abstract class BriarTestCase {
 		// Ensure exceptions thrown on worker threads cause tests to fail
 		UncaughtExceptionHandler fail = new UncaughtExceptionHandler() {
 			public void uncaughtException(Thread thread, Throwable throwable) {
+				throwable.printStackTrace();
 				fail();
 			}
 		};