Added AutoLoader class which does register itself as the autoloader of the current runtime.
Revert "Added AutoLoader class which does register itself as the autoloader of the current runtime."

This reverts commit 0be2b355fa3fb3a022ac24960ae15fd3007da47b.
Added AutoLoader class which does register itself as the autoloader of the current runtime.
The index.php does initialize the Sask class, the AutoLoader will load all needed classes itself without manuell require or include command.
Switched global constants in a class file to class constants.
Added the AutoLoader to the bootstrap.