Bug 93245 [Dialogs] Error messages show up in two locations in the properties dialog
Force an error message: 1) select a Java project 2) open the properties dialog 3) navigate to Java Compiler>Building 4) enable project specific settings 5) enter a letter into the maximum number of problems field ->the error message shows up at the bottom 6) resize the dialog ->the error message also shows up in the banner
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferenceDialog.java
* @see org.eclipse.jface.dialogs.Dialog#cancelPressed()
	 */
	protected void cancelPressed() {
		
		Iterator nodes = preferenceManager.getElements(PreferenceManager.PRE_ORDER).iterator();
		while (nodes.hasNext()) {
			final IPreferenceNode node = (IPreferenceNode) nodes.next();
			if (getPage(node) != null) {
				SafeRunnable.run(new SafeRunnable() {
					public void run() {
						if (!getPage(node).performCancel())
							return;
					}
				});
			}
		}
		setReturnCode(CANCEL);
		close();
	}
	/**
	 * Clear the last selected node. This is so that we not chache the last
	 * selection in case of an error.
	 */
	void clearSelectedNode() {
		setSelectedNodePreference(null);
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.window.Window#close()