Create activities and entities to get closer to Nipype
Ignore pyc files in git repository
Create 2 activities instead of '"statistical_estimation"
Changes suggested on NIDASH call 06/01/2014

- Rename statistical_estimation in model_fitting
- No arrow between contrast_variance_map and staistical_map
- residual_mean_squares and design_matrix as input of
contrast_estimation

And also:
- No arrow between contrast_standard_error_map and
residual_mean_squares_map
Remove coordinateSystem attributes in peaks

Change suggested on NIDASH call 13/01/2014
Add separate coordinateSpace entity

Create two coordinateSpace entity to store voxelToWorldMapping,
voxelUnits, voxelSize, coordinateSystem, dimensions and
numberOfDimensions.

The first entity is member of data_scaling, beta_map_1, beta_map_2,
residual_mean_squares_map, contrast_variance_map, contrast_map,
statistical_map and excursion_set.

The second entity is member of search_space
Remove `hadMember` relationships ( `coordinateSpace` )

Replace `hadMember` relationships by `nidm:hasCoordinateSpace`
attributes.
Merge pull request #18 from cmaumet/spmUpdate

Update SPM data model according to NIDASH calls on 16th of Dec, 6th and 13th of January