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
* @param roots the save roots
		 */
		public SaveFilter(IResource[] roots) {
			this.roots = roots;
		}
		
		/* (non-Javadoc)
		 * @see org.eclipse.ui.ISaveableFilter#select(org.eclipse.ui.Saveable, org.eclipse.ui.IWorkbenchPart[])
		 */
		public boolean select(Saveable saveable,
				IWorkbenchPart[] containingParts) {
			if (isDescendantOfRoots(saveable)) {
				return true;
			}
			
			for (int i = 0; i < containingParts.length; i++) {
				IWorkbenchPart workbenchPart = containingParts[i];
				if (workbenchPart instanceof IEditorPart) {
					IEditorPart editorPart = (IEditorPart) workbenchPart;
					if (isEditingDescendantOf(editorPart)) {
						return true;
					}
				}
			}
			return false;
		}
		
		/**
		 * Return whether the given saveable contains any resources that
		 * are descendants of the root resources.