* Don't lowercase element names and attribute names in selectors
https://www.w3.org/TR/css3-selectors/#casesens
> All Selectors syntax is case-insensitive within the ASCII range (i.e.
> [a-z] and [A-Z] are equivalent), except for parts that are not under the
> control of Selectors. The case sensitivity of document language element
> names, attribute names, and attribute values in selectors depends on the
> document language. For example, in HTML, element names are
> case-insensitive, but in XML, they are case-sensitive.
Fixes#3304.
* Fix number normalization in selector interpolation
* Split Less and SCSS parsing into different parsers
Now, .less files are always parsed with postcss-less, and .scss files
areare always parsed with postcss-scss. This:
- Is less hacky.
- Is meant to avoid issues like #2829.
- Is probably more performant.
`parser: "postcss"` and `--parser postcss` continue to work like before:
First trying postcss-less, and if that fails, postcss-scss, unless a
regex says that we should try in the opposite order. The new values for
the parser option are "postcss-less" and "postcss-scss".
* Remove postcss from package.json since it is not used
* Rename parser-less to less and parser-scss to scss
* Deprecate parser:postcss in favor of parser:css
* Fix CSS tests
Fixes#2820. While that issue is about `@media (--fooBar)` in
particular, this commit changes to never lowercase stuff starting with
`--` in general, as it seems like those `--customStuff` things can pop
up kind of anywhere.