Air Pollution: using standard "from" dir for wind

[#67037632]
rm img tag requesting nonexistent & unused image
Air Pollution: rename "factories"->"power plants"

[#66449336]
Air Pollution: widen labels for "power plant" rename

[#66449336]
Air Pollution: put sliders below playback

[#66449336]
[#64616426]
Air Pollution: fix label pos for "wide" sliders

[#66449336]
Also fix center label position for wide sliders

[#66449336]
Air pollution: fix lying car pollution rate slider

[#67038102]
Air Pollution: fix dir, linearity of pollution

[#67038102]

Previously, moving the pollution sliders to max turned pollution off. Additionally, pollution wasn't linearly related to the rate, it was a surprising 1/x relationship instead.
Don't change max {car|power plant} pollution rates

[#67038102]
Match previous pollution rate initial values

[#67038102]

The initial values themselves probably need to be adjusted, but for now this keeps the effective pollution rate in the various Air Pollution interactives the same as it was before the logic that detects when to emit pollution was tweaked.
Air pollution models: Automatically set root vars
Whitespace
Air Pollution: rm model default setup from UI code

Helps with [#66948674]
Air Pollution: rename confusing variable names
rename carElectricRate -> electricCarPercentage
Air Pollution: now we can simplify variant setup

Helps with [#66948674]
Air Pollution: increase pollution rates in #2, #4

[#66948674]
Air Pollution Aerial: NGS images w/o layout change

[#65235564]
Air Pollution Aerial: tweak layout for NGS imgsize

[#65235564]