Sticky Menu (earlier: Fixed broken snapshots for cells with background views)

[benjaminjackson]

This isn't 100% ready but wanted to float it out there in case anyone has ideas: I fixed the bug where cells with background views don't display when swiping.

There's a catch, though: the separators aren't rendering in the simple case (no background view), which looks weird when the color background highlights itself—i.e. the separator turns green when hitting the trigger point.

Any suggestions for how to fix this pull to the point where it's worth accepting would be welcome.

[alikaragoz]

Thanks for the report and PR @benjaminjackson, I hope to have some time to look at it during the weekend. I'll keep you informed.

[benjaminjackson]

Just realized I still had this pull open and pushed some other, unrelated changes to master, so this pull now includes a new "sticky menu" mode that will mimic Apple Mail's Archive button.

I started going to the trouble of opening a new branch and rebasing but am not amazing at git so feel free to cherry-pick either or both of the commits in the pull.