Fix for #1985: ensure that the AxisNameID in the STAT table is > 255 (#1986)

Fix for #1985:
* ensure that the AxisNameID in the STAT table is not less than 256. This needed an additional argument to the addMultiLingualName() name table method.
* fvar axis name IDs must also not be less than 256, just like STAT axis names.
5 files changed