Changes:
- Fix a bug where * wouldn't always be eliminated during selector unification.
Deprecations -- Must Read!
- Extending compound selectors such as .a.b is deprecated. This never followed the stated semantics of extend: elements that match the extending selector are styled as though they matches the extended selector.
- When you write h1 {@extend .a.b}, this should mean that all h1 elements are styled as though they match .a.b—that is, as though they have class="a b", which means they'd match both .a and .b separately. But instead we extend only selectors that contain both .a and .b, which is incorrect.
- Color arithmetic is deprecated. Channel-by-channel arithmetic doesn't correspond closely to intuitive understandings of color. Sass's suite of color functions are a much cleaner and more comprehensible way of manipulating colors dynamically.
- The reference combinator, /foo/, is deprecated since it hasn't been in the CSS specification for some time.
- The old-style :name value property syntax is deprecated. This syntax is not widely used, and is unnecessarily different from CSS.