Merge pull request #4 from bgruening/master

Small fixes and optimisations
progress on fit and fit_transform
progress on fit and fit_transform
progress on fit and fit_transform
introduced min_r and min_d; added sequence_motif.py
max-motif-size in sequence_motif
improved fit: now full parameter optimization
bugfix
bugfix
bugfix
bugfix
bugfix
bugfix
bugfix
bugfix
improved motif finder; now called max_subarray.py
added add_negative_sequence_data.py