Implemented SlopeOne.
Moved recommender to recommender/ and utilitie stuff to util/
Corrected a wrong indent.
Corrected the new imports.
Addded BPRMF so it can be directly called.
Added a file for RankMFX so it can be directly called.
Added a docstring to the bin package.
Addded a docstring to the recommender package.
Renamed tabSepReader to stringSepReader and added a paramater so the

reader can read in text files where the columns are seperated by an
arbitrary string which has to be specified in the second argument.
Moved the functions of external.py into helper.py.
Wrote the docstring for the util package.
Added many docstrings.