Issue 4068: Make the auto logout more obvious

https://code.google.com/p/otwarchive/issues/detail?id=4068

If someone could write some text about cookies going missing ? I can update this with some proper text.
The separate elements for the text and the link sets i18n alarm bells ringing in my mind as the link might not be the last thing in the text in all languages. It looks as if recent examples of embedding the support link into a block of text were resolved by putting the link in the ts and adding an .html_safe to the ts. That would give us:

```ruby
<p><%= ts("You have been automatically logged out to protect your privacy.  
Please make sure that your browser is set to accept cookies from
archiveofourown.org and delete any existing Archive cookies. If you continue 
to have problems logging in, please <a href=\"#{new_feedback_report_url}\">contact Support</a>.".html_safe)%></p>
```

Having said, I couldn't find many examples where we had links inside translatable text, so it might require a second opinion.