Upgrade or remove jQuery

[hcayless]

We're still using an old version of jQuery, and it's causing warnings.

[ryanfb]

Note that PE SoSOL also currently uses jQuery loaded from PN in order to resource-share: https://github.com/sosol/sosol/blob/master/app/views/layouts/pn.html.erb#L21

If we pull it from use in PN, the file probably needs to still be there for use by PE until we deploy a version of PE that hosts its own (upgraded) version. See also this issue for moving PE to the Rails asset pipeline (it looks like I did some experimental work on a branch there to move things over to the asset pipeline which required self-hosting an upgraded jQuery): sosol/sosol#97