IDPF/epubcheck — pull request #449 by rdeltour (2014-09-05 08:13:28+00:00)
Title: Accept the `inherit` keyword as a relative font size

Without looking at the inheritance chain, there's no way to properly tell if a `font-size` property with the `inherit` value is relative or fixed, so simply adding `inherit` as an accepted "relative" keyword.

Should fix #441 , although `ACC_014` should already be set to `USAGE