Fit-Check added to NiftiLabelsMasker
changed exception type + unit tests pass now
fit-check for Nifti([Labels, Maps])Masker + type in BaseMasker corrected
de-sniggle-ized
Merge pull request #267 from banilo/masktransf

[ENH] Fit-Check added to NiftiLabelsMasker
reorder_img 'resample' argument sets interpolation resampling

Also:
* niimg variable names should end with _img in test_resampling.py
* fix PEP8 and typo axis -> axes
* add value of interpolation in resample_img error message