[XeTeX] Fontspec: Historic not Historical Ligatures?

[David Perry]

I just updated my fontspec (along with other packages in MiKTeX) and got 
errors when using the OT Historical Ligatures feature.  After a moment 
of panic, since I am working like crazy to finish a book, and after 
checking my Linux Libertine font again, I read the new fontspec docs.

Why has Historical become Historic?  According to 
http://www.microsoft.com/typography/otspec/featurelist.htm, "historical" 
is the official name.

I certainly don't object to changes that solve problems or make it 
easier to improve packages down the line, even if such changes cause 
difficulties in transition.  But this one seems both strange and 
unnecessary, and apt to break existing documents.  Comments?

David