Don't store keys on elements; don't think we need 'em

Test Plan:
hack hack hack

Conflicts:
	src/widgets/interaction.jsx
Properly handle visiblity state when reordering

Test Plan:
hack hack hack

Conflicts:
	src/widgets/interaction.jsx
Fix showing/hiding of grid settings

Test Plan:
hack hack hack
Add label support to interaction widget

Test Plan:
hack hack hack
Actually fix cherry-pick conflicts

This branch isn't actually supposed to be merged with anything, so the history's a bit of a mess