[Laszlo-dev] Do we still need mapTextMetricsCompilation?

[P T Withington]

I'm trying to remodularize some stuff in the schema to pass around classModels 
everwhere (instead of tagnames that get looked up over and over) and this is 
the only caller of `schema.getBaseClassname`.  If that is all crud, I'd like to 
rip it out.