Classloader und Database verändert

ClassLoader:
 Initialize the static components in ClassLoader

Like any other PHP static variable, static properties may only be
initialized using a literal or constant; expressions are not allowed.
Therefore, the static init() function, which is called at the end of
the php file, has been added.

Database:
 add static function Database::generateORClauseToSimulateINClause ()

Generate a WHERE clause by using ORs to use as
"column IN (comma seperates values)"