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
protected Control createContents(Composite parent) {
	
	
	initializeDialogUnits(parent);
	
	GridLayout layout = new GridLayout();
	layout.numColumns = 2;
	layout.marginHeight = convertVerticalDLUsToPixels(IDialogConstants.VERTICAL_MARGIN);
	layout.marginWidth = convertHorizontalDLUsToPixels(IDialogConstants.HORIZONTAL_MARGIN);
	layout.verticalSpacing = convertVerticalDLUsToPixels(IDialogConstants.VERTICAL_SPACING);
	layout.horizontalSpacing = convertHorizontalDLUsToPixels(IDialogConstants.HORIZONTAL_SPACING);
	layout.makeColumnsEqualWidth = false;
	parent.setLayout(layout);
	parent.setLayoutData(new GridData(GridData.FILL_BOTH));
	
	
	dialogArea = createDialogArea(parent);
	buttonBar = createButtonBar(parent);
	
	
	return parent;
}
/*
 * @see Dialog.createButtonBar()
 */
protected Control createButtonBar(Composite parent) {
	
	Composite composite = new Composite(parent, SWT.NONE);
	
	GridLayout layout = new GridLayout();