use ~2.1 when depending on the ClassLoader component
updated required versions when depending on the Finder component
updated required versions when depending on the Process component
updated required versions when depending on the Stopwatch component
updated required versions when depending on the EventDispatcher component
updated required versions when depending on the Routing component
updated required versions when depending on the DependencyInjection component
updated required versions when depending on the Config component
updated required versions when depending on the HttpFoundation component