Hazard icons, a movable feedback box, and table fixes

Hazard pictograms now show OSHA's actual artwork instead of a lookalike icon. The feedback dialog can be dragged out of the way, and now takes screenshots and a link to what you're describing. The items table defaults to chemical, CAS number, grade, hazards, size and location, and reordering columns now works on a phone. A zoomed-in photo can be dragged with a mouse to pan around it.