Refactoring of content objects of tslib_content
The class tslib_content is a "monster" class having all content objects + helper functions.
The patch use classes for each single content object, they are only instantciated when they are needed. Additional the classes and tslib_content are cleaned by using CGL.
This refactor was a result from the T3DD10 workshop "Pimp Your Typoscript"
(issue imported from #M15094)