Add versioned links to RDF, OPDS and JSON links (closes #154)

Main contribution: lookup query parameter `v` and if it's there, add the same parameter + value to links to RDF, JSON and OPDS views of the data. I had asked for this in issue #154.

There was a form with end element the same as start element: `<form>` instead of `</form>`.

And 

> Are you sure you want to remove ... _for_ your list?

is now

> Are you sure you want to remove ... _from_ your list?