[css3-exclusions] wrap-margin and wrap-padding properties

It's unclear from the spec, but I presume these will accept one to four
values as with the margin and padding properties. If that's the case, won't
we also need individual properties:

wrap-margin-bottom
wrap-margin-left
wrap-margin-right
wrap-margin-top
wrap-padding-bottom
wrap-padding-left
wrap-padding-right
wrap-padding-top

The wrap shorthand property already has the forward slash in the syntax to
permit multiple values.