5.4 is a new major release so we don't have to be 100% backwards compatible. Hence this is the chance to upgrade third party libs. We should investigate for all libs, whether there's newer versions around and whether we should use them.

Few examples:

• commons-beanutils: 1.8.3 -> 1.9.2
• selenium: 2.41.0 -> 2.42.2
• htmlunit: we're using 2.8 but there's 2.12
  Because of API changes this requires adapting AbstractMagnoliaHtmlUnitTest#openPage e.g. as follows:

          final WebClientOptions webClientOptions = webClient.getOptions();
  
          webClientOptions.setRedirectEnabled(followRedirects);
  
          // we also want to test error code handling:
          webClientOptions.setThrowExceptionOnFailingStatusCode(false);
  
          webClientOptions.setCssEnabled(true);
          webClientOptions.setJavaScriptEnabled(enableJsvascript);