Shot page titles should include 'Firefox Screenshots'

[jaredhirsch]

(Did we wontfix this bug already?)

From https://twitter.com/georgebaily/status/927520943903268864:

" hm, Firefox screenshot tool is cool and all, but setting the title as not just http://screenshots.firefox.com but also the page you screenshotted, means you get lots of false positives from browser history when typing a URL / bookmark "

[ianb]

The <title> tag does include Screenshot:. Oddly the tab title and history title doesn't include this?

There are several title-like things on the page, including og:title, twitter:title. BUT: I believe the issue here is that we set document.title! That's not intentional.