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
selectedResource = (IResource) ((IAdaptable) object)
							.getAdapter(IResource.class);
				}
				if (selectedResource != null) {
					if (selectedResource.getType() == IResource.FILE) {
						selectedResource = selectedResource.getParent();
					}
					if (selectedResource.isAccessible()) {
						resourceGroup.setContainerFullPath(selectedResource
								.getFullPath());
					}
				}
			}
		}
	}
	/**
	 * Sets the value of this page's container name field, or stores it for
	 * future use if this page's controls do not exist yet.
	 * 
	 * @param path
	 *            the full path to the container
	 */
	public void setContainerFullPath(IPath path) {
		if (resourceGroup == null) {
			initialContainerFullPath = path;
		} else {
			resourceGroup.setContainerFullPath(path);
		}
	}
	/**