The only ways this varies from the `scale()` function is with parsing
and serialization. Parsing stays separate, and serialization is done by
telling `TransformationStyleValue` which property it is, and overriding
its normal `to_string()` code for properties other than `transform`.
This reverts commit 76daba3069.
We're going to need separate types for the JS-exposed style values, so
it doesn't make sense for us to match their names with our internal
types.
Use discrete animation when the number of components or the types
of corresponding components do not match. This commit does not cover
all cases, but adds FIXME comments in the appropriate places.
