Definition of "ClusterDefinitionCriteria"
Suggestion for related definitions
connected18In3D -> voxel18Connected
Definitions related to Voxel and Pixel connectivity

as discussed in https://github.com/incf-nidash/nidm/pull/201
Update terms README
Update Prov store links
Merge pull request #201 from cmaumet/clusterDefinitionCriteriaDefinition

Definition of "ClusterDefinitionCriteria"