Add support for ID-ranges

[dalito]

To establish unique numeric IDs it is reasonable to uses pre-allocated ID-ranges that are centrally coordinated. All contributors get their own ID-range that they manage themselves. Once all IDs from a pre-allocated range are consumed a new range must be requested, e.g. via an issue-form (example, github-docs).

To manage which range is assigned to which contributor, ID-ranges should be specified in a config file.

This idea has been working well in my group for sample-IDs and is also used by OBO Foundry which maintain per-allocated ID-ranges in a file "idranges.owl" that is placed and managed in the ontology repository on github.