handling of att.handFeatures attributes

[riedde]

In the commens-specs file there is a modification of <handNote> (L2642). The attribute class att.handFeatures is deleted and the attributes @scribe and @scope are defined. Why isn't the attribute class modified directly?
By chaining the ODD I have the problem that I have to redefine those attributes in the same way than it is done in the WeGA-ODD. My idea was to create a class for HenDi specific handling of those handFeatrues but this does not work. (I thought about this because I'll need the same definition at <handNote> and <handShift> and I like to avoid multiple definitions of the same thing.

Maybe we can together have a look at this, some time. (For the moment I redefined those attributes twice)

[riedde]

It was a bit tricky but with adding the missing attribute class and modifying it the issue has been resolved.