Include the full stack trace in exception message

The format of this error message used to look like:

```java
Expected number (0) of Non-OK status objects in log differs from actual (1).
	Error while parsing /projC_testTripleDownwardV/h3.h. java.lang.reflect.InvocationTargetException

Caused by: java.lang.reflect.InvocationTargetException
Caused by: java.lang.AssertionError: Need to hold a write lock to clear result caches
```

and it was hard to impossible to identify what the cause is.

The hope is that capturing this fuller stack trace into the log
will make it easier to identify the problem.

Part of #117

core/org.eclipse.cdt.core.tests/suite/org/eclipse/cdt/core/testplugin/util/LogMonitoring.java

@@ -10,6 +10,8 @@
  *******************************************************************************/
 package org.eclipse.cdt.core.testplugin.util;
 
+import java.io.PrintWriter;
+import java.io.StringWriter;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -72,9 +74,15 @@ void stop(int expectedLoggedNonOK) {
 							cause = cause != null ? cause : t;
 							if (t != null) {
 								msg.append(t.getMessage() != null ? t.getMessage() : t.getClass().getCanonicalName());
+								msg.append("\nStack Trace\n");
+								StringWriter writer = new StringWriter();
+								PrintWriter out = new PrintWriter(writer);
+								t.printStackTrace(out);
+								msg.append(writer.toString());
+
 							}
 
-							msg.append("\n");
+							msg.append("\n\n");
 						}
 					}
 				}