[NTG-context] proportional oldstyle figure not working in MKIV

Hi, Hans: I think there are problems with the current MKIV font loading code. sample code: \definefontfeature[minion][language=dflt, script=latn, onum=yes, kern=yes, pnum=yes] \definefontsynonym[Minion][MinionPro-Regular][features=minion] \definefont[Minion][Minion at 34pt] \starttext \Minion 1234567890 \stoptext This works in MKII (XeTeX). Please fix that. Thanks Yue Wang