Merge branch 'split/core' of https://github.com/contao/core into hotf…
…ix/4.3.8 # Conflicts: # src/Resources/contao/classes/FrontendTemplate.php # src/Resources/contao/dca/tl_templates.php # src/Resources/contao/forms/FormTextArea.php # src/Resources/contao/library/Contao/Controller.php # src/Resources/contao/library/Contao/Environment.php # src/Resources/contao/library/Contao/Image.php # src/Resources/contao/library/Contao/StringUtil.php # src/Resources/contao/library/Contao/System.php