Base classes are not new-style classes

The base classes for the Preprocessor, Extractor and Algorithm are not new-style classes (i.e., the do not derive from object). Hence, calling super does not work with them:, it generates the same error message as here: http://stackoverflow.com/questions/1713038/super-fails-with-error-typeerror-argument-1-must-be-type-not-classobj

Also, calling of base class functions (including constructors) do not use super yet.