WIP: Update FSL model

* Add `coordinateSpace` entities
* Add `Stats` activity
* Add `Parameter estimates` (beta maps)
* Add `Design matrix`
* Remove link between `Statistical estimate` and `Contrast estimate`
fix: Remove contrastName in betaMap_2
add: statisticType attribute in contrast_id
add: one-tailed or two-tailed test
Replace `prov:atLocation` by `prov:location`
`centerOfGravity` in `fsl` namespace
Replace `nidm:hasCoordinateSpace` by `nidm:coordinateSpace`
Replace `prov:atLocation` by `prov:location`

As suggested in PR #20 for FSL update.
Replace `nidm:hasCoordinateSpace` by `nidm:coordinateSpace`

As suggested in PR #20 for FSL update.
Update png graphs and json
Update png graph
Update json serialisation
add: oneTailed or twoTailed test attribute
Change prove:label in contrast_id to be coherent with prove:type
Update png graphs
Update json serialisation
Merge pull request #20 from cmaumet/fslUpdate

WIP: Update FSL model
Merge branch 'master' of github.com:ni-/ni-dm
rebasing, conflicts in FSL graphs files
Merge pull request #22 from cmaumet/spmUpdate

WIP: Update SPM model