New SVG icons from UI team

@cleercode

Not sure about the disabled fill recommendation: opacity worked with any color, unlike this.

Fixes #2478 
And by the way, changing the foreground color has no effect on SVGs, unlike `opacity` or `fill`. Normally one would use `fill` for that, however the button in question here doesn't use `<img>` - it uses `background-image`, and that one is very limited in what you can control about it. `opacity` is one of the few things that work.