We did already have range checking for the `<integer>` and `<number>`
types, but this patch adds this functionality to all numeric types
(dimensions and percentages).
The syntax in Properties.json is taken from the spec:
https://www.w3.org/TR/css-values-3/#numeric-ranges
eg, `length [0,∞]` defines that a Length is allowed as long as it has a
positive value.
The implementation here allows for any number to be the positive or
negative limit, even though only 0 and positive/negative infinity are
meaningful values without a unit.
d6901d2119
