1. Modify Nc4Iosp to deal with the fact that as of version
3.0.9 of jna, the getArrayString(int,int) does not exist.
It is in, at least, 4.0.0, but that is not yet
available thru the maven jar repository.

2. Modify EnumTypedef to handle the fact that enum consts may be
signed or unsigned, but EnumTypeDef does not signedness info.