Convenience offset on end of resource urls: /raw, /api

[rgrp]

/dataset/{id}/resource/{resource-id}/raw

=> redirects to resource url (download)

/dataset/{id}/resource/{resource-id}/api[/....]

=> either redirects or directly serves /api/data/{resource-id}

Assigning for kindly for review.

These would take about 20m to implement and would be *very* convenient from my experience of using the data API.