IIIF paths and dereferencability

[ghukill]

An interesting head-scratcher, put on hold for now.

Some background:
https://groups.google.com/forum/#!searchin/iiif-discuss/canvas$20URI%7Csort:relevance/iiif-discuss/HZtInSSs_8k/mP_dbBxsAwAJ

If we create URL patterns like:
/item/<PID>/iiif/manifeset.json

this is problematic if we want to create canvas URIs with the recommended pattern:
/item/<PID>/iiif/canvas/<DS>.json

because we are using iiif-prezi, and building our base path in such a way that we include the originating PID at the base of the URL. However, this presents a problem if a canvas is from another PID, as is the case with ebooks.

One solution would be to offer a more generic, /iiif where all manifests and Canvas URIs would stem from. But, if canvas URIs aren't needed, than our current approach is fine...

Just some notes here for now.