Bug 118516 [DataBinding] Asserts should provide meaningful messages
Currently we use JDK Assert in various places in the code. However, if an assert fails, there often is no indication of why it failed or what the assert failure means without looking at the code indicated by the stack trace. It would be nicer if we would log exceptions or throw RuntimeExceptions with useful error messages instead.
bundles/org.eclipse.core.databinding/src/org/eclipse/core/databinding/observable/AbstractObservable.java
/**
	 * @param realm
	 */
	public AbstractObservable(Realm realm) {
		super(realm);
	}
	public synchronized void addChangeListener(IChangeListener listener) {
		addListener(ChangeEvent.TYPE, listener);
	}
	public synchronized void removeChangeListener(IChangeListener listener) {
		removeListener(ChangeEvent.TYPE, listener);
	}
	public synchronized void addStaleListener(IStaleListener listener) {