Detect accidental property resets

[gmetais]

I've just read this interesting article about accidental reset:
http://css-tricks.com/accidental-css-resets/

It might be interesting to detect this kind of mistake. Or it could just be taken in account in "duplicatedProperties".

[macbre]

• MDN docs
• css-shorthand-properties npm module by @gilmoreorless

[macbre]

The example:

.foo {
  background-color: red;
  background: url(images/bg.gif) no-repeat top right;
}

will yield:

.foo: "background" resets "background-color" property set earlier