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
/**
	 * The persistent property key used on IFile resources to contain the
	 * preferred editor ID to use.
	 * <p>
	 * Example of retrieving the persisted editor id:
	 * 
	 * <pre><code>
	 *  IFile file = ...
	 *  IEditorDescriptor editorDesc = null;
	 *  try {
	 *  	String editorID = file.getPersistentProperty(EDITOR_KEY);
	 *  	if (editorID != null) {
	 *  		editorDesc = editorReg.findEditor(editorID);
	 *  	}
	 *  } catch (CoreException e) {
	 *  	// handle problem accessing persistent property here
	 *  }
	 * </code></pre>
	 * 
	 * </p>
	 * <p>
	 * Example of persisting the editor id:
	 * 
	 * <pre><code>
	 *  IFile file = ...
	 *  try {
	 *  	file.setPersistentProperty(EDITOR_KEY, editorDesc.getId());
	 *  } catch (CoreException e) {
	 *  	// handle problem setting persistent property here