Bug 172000 [Wizards] WizardNewFileCreationPage should support overwriting existing resources
In the WizardNewFileCreationPage, there should be a method to set allowExistingResources flag for ResourceAndContainerGroup member. It is useful when both "create" and "renew/overwrite" operations are meaningful for a wizard.
bundles/org.eclipse.ui.ide/extensions/org/eclipse/ui/dialogs/WizardNewFileCreationPage.java
.openError(
							getContainer().getShell(),
							IDEWorkbenchMessages.WizardNewFileCreationPage_internalErrorTitle,
							NLS
									.bind(
											IDEWorkbenchMessages.WizardNewFileCreationPage_internalErrorMessage,
											e.getTargetException().getMessage()));
			return null;
		}
		newFile = newFileHandle;
		return newFile;
	}
	/**
	 * Returns the scheduling rule to use when creating the resource at the
	 * given container path. The rule should be the creation rule for the
	 * top-most non-existing parent.
	 * 
	 * @param resource
	 *            The resource being created
	 * @return The scheduling rule for creating the given resource
	 * @since 3.1
	 * @deprecated As of 3.3, scheduling rules are provided by the undoable
	 *             operation that this page creates and executes.
	 */
	protected ISchedulingRule createRule(IResource resource) {
		IResource parent = resource.getParent();
		while (parent != null) {
			if (parent.exists()) {
				return resource.getWorkspace().getRuleFactory().createRule(
						resource);