Share a link (from H.) that adds H to the current page

[dwhly]

As a user, I want to be able to easily share a link with someone that lets them see the annotations on a page and/or create some of their own without having the extension.

@ikreymer's PyWB+H. project may come in handy here. :)

The URL for sharing might look something like: http://via.hypothes.is/http:///

[dwhly]

This was delivered by the https://github.com/hypothesis/via effort. Repurposing this issue to focus on the ability to now share this capability directly from the h. application interface.

For sites that embed H. natively, there's no need for this feature of course, since just providing a link to the source page is sufficient-- so this should be conditional on the extension, or on H. as embedded by this feature.

[BigBlueHat]

@hypothesis/developers could we make this a parameter when loading the sidebar and default the /stream document URLs to use Via? Handling the "presence" of the extension could be a follow-up issue (and not part of the acceptance criteria for this one).

User Stories

• As someone exploring Hypothes.is Stream page, I want links to annotated documents to show those annotations, so that I can join in the annotation goodness.
• As a developer deploying h, I want to configure my own proxy URL (other than via.hypothes.is), so that I can control the URL embedding h for my users.

Comparison Grid

	Stream	Embed.js Sidebar	Extension Sidebar
hypothes.is using via	yes	no	no
self-hosted h (optional via install)	configurable	no	no