Bug 174272 FileStoreEditorInput needs to be restorable
3.3 M5 The FileStoreEditorInput needs to restorable on startup. Therefore it needs to return an IPersistableElement and there needs to be an element factory.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/ide/IDE.java
* @since 3.1
	 */
	public static IEditorDescriptor getEditorDescriptor(String name,
			boolean inferContentType) throws PartInitException {
		if (name == null) {
			throw new IllegalArgumentException();
		}
		IContentType contentType = inferContentType ? Platform
				.getContentTypeManager().findContentTypeFor(name) : null;
		IEditorRegistry editorReg = PlatformUI.getWorkbench()
				.getEditorRegistry();
		return getEditorDescriptor(name, editorReg, editorReg.getDefaultEditor(
				name, contentType));
	}
	/**
	 * Get the editor descriptor for a given name using the editorDescriptor
	 * passed in as a default as a starting point.
	 * 
	 * @param name
	 *            The name of the element to open.
	 * @param editorReg
	 *            The editor registry to do the lookups from.
	 * @param defaultDescriptor
	 *            IEditorDescriptor or <code>null</code>
	 * @return IEditorDescriptor
	 * @throws PartInitException
	 *             if no valid editor can be found
	 * 
	 * @since 3.1
	 */