fixed stupid DATA_DIR value
removed bangs
implemented code computing for joint histogram 2 3D vols
minor fixes
added fMRISTC class for dealing explicitly with fmri filenames
added support for image objects (nibabel) in fit(..) method
pretty string for updating progress bar
Merge branch 'motion-correction' of https://github.com/dohmatob/pypreprocess into motion-correction
minor fixes
minor updates to spike code