Bug 24157 [Dialogs] MessageDialog needs to setFocus on default button
As the MessageDialog by default has no other widgets to set focus on we need to set focus on the default button to prevent it getting slammed by the default SWT behaviour.
bundles/org.eclipse.jface/src/org/eclipse/jface/dialogs/MessageDialog.java
* Creates and returns the contents of an area
 * of the dialog which appears below the message and
 * above the button bar.
 * <p>
 * The default implementation of this framework method
 * returns <code>null</code>. Subclasses may override.
 * </p>
 *
 * @param the parent composite to contain the custom area
 * @return the custom area control, or <code>null</code>
 */
protected Control createCustomArea(Composite parent) {
	return null;
}
/**
 * This implementation of the <code>Dialog</code> framework 
 * method creates and lays out a composite and calls 
 * <code>createMessageArea</code> and <code>createCustomArea</code>
 * to populate it. Subclasses should override <code>createCustomArea</code>
 * to add contents below the message.
 */
protected Control createDialogArea(Composite parent) {
	
	
	createMessageArea(parent);
	
	
	Composite composite = new Composite(parent, SWT.NONE);
	GridLayout layout = new GridLayout();
	layout.marginHeight = 0;