Fix file headers.
Switch to new code style.
Change tab to space indention.
Reformat dca files.
Reformat code.
Drop obsolete classes.
Reorder directory structure.
Merge branch 'tng' into rework-sorting

Conflicts:
	contao/config/config.php
	src/MetaModels/BackendIntegration/Boot.php
	src/MetaModels/BackendIntegration/InputScreen/IInputScreen.php
	src/MetaModels/BackendIntegration/InputScreen/InputScreen.php
	src/MetaModels/BackendIntegration/ViewCombinations.php
	src/MetaModels/DcGeneral/Dca/Builder/Builder.php
	src/MetaModels/DcGeneral/Events/Subscriber.php
	src/MetaModels/Filter/Setting/Simple.php
	src/MetaModels/Helper/UpgradeHandler.php
	contao/dca/tl_metamodel_dca.php