Supports General.Changes

Draft 2.1

• Forbid "and" or "or" tokens at the beginning of InterpolatedAnyValue in SupportsAnything. This makes more explicit the fact that the SupportsCondition parsing takes precedence.

Draft 2

• Mark the InterpolatedAnyValue productions as optional. According to Tab Atkins, this matches the intended (although not the written) syntax of the CSS spec.

• Add Interpolation as an option for SupportsInParens, for backwards-compatibility with existing Sass behavior.

Draft 1

• Initial draft.