Parse language of cmap subtables
Parse language of cmap subtables

And use it when checking subtable order. Fixes #16, though the cmap
table of the font in question is still rejected because we don’t support
parse format 6 subtables.

davelab6/ots,irori/ots,anthrotype/ots,anthrotype/ots,davelab6/ots,khaledhosny/ots,irori/ots