Update serialisations for SPM examples
Update serialisations for SPM examples

Applying modifications suggested by @cmaumet.
Merge pull request #24 from gllmflndn/master

Update serialisations for SPM examples
Small updates in labels and associate activities with software
Merge with upstream
Update labels (instance) and associate activities with agent

- Update `prov:label` in `niiri:contrast_standard_error_map_id`,
`niiri:extent_threshold_id` to have instance-specific labels
- add a wasAssociatedWith relationship between all activities and
software agent.