Fix typo in error message
updated ROI extraction
ROI example: second version
Now Subplots and boxplots
PEP8ized + more intuitive variable names
Fit-Check added to NiftiLabelsMasker
Remove explicit mention of NiftiMasker from BaseMasker
changed exception type + unit tests pass now
variable renaming + cosmetics
fit-check for Nifti([Labels, Maps])Masker + type in BaseMasker corrected
Adapted .rst files for Sphinx
de-sniggle-ized
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
Create nilearn_data as a working dir for _get_dataset_dir
Change logic for searching dataset dir
Catching all exceptions and reporting at the end
Test clause on non-directories
change work inside temporary directory in get dataset dir test
Regexp control on raised errors
Different environment setup testing
_get_dataset_dir error message string