Add support for Ranges to build a table of contents

[tpendragon]

We have an immediate need for a table of contents for organizing audio tracks on a playlist, but if we wanted to use Clover for books we'd definitely need a table of contents for navigating different sections.

In UV it looks like this:

[mathewjordan]

Relating this to IIIF-Commons/iiif-helpers#14 and the eventual inclusion in iiif-helpers