Button to hide closed-access papers

[steveharoz]

@janwillemtulp's suggestion:

maybe you should also have a filter on "not available / available" (for me the ones not available make no sense anyway), and at the top en indication of the ratio of the available papers which are open access?

[steveharoz]

Notes

A button can hide ".closedAccess"

Because it's at the same level in the DOM as paper track (infovis, vast, etc.), the buttons interfere with each other.

To reproduce issue: Hide journal. Hide closedAccess. Unhide closedAccesss.
Result: Some journal papers (closed access ones) are now visible.
Solution: Put closed access at a different DOM level, so it doesn't interfere with the conference track visibility.