Add a 'Dancing Shoes'-like API for de/constructing the features.fea into js objects

[davelab6]

In posting to http://typedrawers.com/discussion/920/opentype-substitution-many-to-many-replace-sequence-by-another-sequence I'm reminded of a recent comment in Metapolator G+ that it ought to adjust and inter/metapolate anchor points and OpenType GPOS feature files values... I've always found the custom syntax of Adobe's FEA distasteful, especially since its only for the low level opentype features, and lacks higher level representations so you have to deal with things for yourself, like many to many substitutions as in that forum thread, or table breaks to avoid overflows...

So to make ufoJS the best ufo environment, I offer the idea of including a 'Dancing Shoes'-like API for de/constructing the features.fea into js objects

[graphicore]

I agree that something like this is needed. FEA is a pita.