Added MammouthJobGenerator do handdle the special ppn

Fixes #46
Removed debug print.
Added unit test for MammouthJobGenerator
Moved the import of re at the top.
Removed unused import.
Added job_generator_factory test and fixed a bug in job_generator_factory.
Merge pull request #48 from mgermain/mammouth_gen

Added MammouthJobGenerator do handdle the special ppn