Avoid duplicates in fontstack, reset only when fontfamily is null
Do not inherit fontfamily when language differs

If there is no explicit font for this language, it will
inherit the webfont for the parent.
But that is undesirable since language is different.
So inherit the original font of the element.
Define it explicitly so that inheritance is broken.
Merge pull request #31 from santhoshtr/bug49151

Do not inherit fontfamily when language differs