I should be able to compose a serious mailto: link in Querki

Summary: I believe I'm going to want this soon for the Arisia Press Space.

Note that this is not saying that Querki should be able to send emails -- we might do that someday, but it's a dangerous spam vector. But it's entirely reasonable for a page to have a link that, when clicked, pops up a pre-filled-in email in, eg, Gmail.

The issue here is that QText's capabilities are simply too limiting: you can't put everything needed inside of a standard link expression. And the subject and body need to be fully URL-encoded in order to work. So I believe that we're going to have to do this server-side with some HtmlWikitext.

See the RFC for precise details about how this works.

I think we're looking at a new _openEmail() function, with optional text parameters for all of the legal fields. It will URL-encode all the parameters, and compose them correctly using ? and &, so that you can set up relatively arbitrary emails.

The email window should pop open a new window.