Add back button to incident pages to aid in navigating back to queue/all incidents

[noah-schechter]

I find myself needing to think about how to get back to a specific search or category of the queue; I think adding a back button (and adding the necessary memory of a past search (which I think you did recently)) could really help.

This would be an arrow on the top left, like on Twitter.

[milesmcc]

The browser back button should now always work?