nodeffiwriter: find the right namespace

when you use, for example, SDB.Sdb, nodeffiwriter generates inconsistent code:
in particular, when you use the type it generates something like:
   sdb: _.ref(_.SDBSdb)

but when the writer visits the class SDB.Sdb it refers to the it as _.Sdb.
This patch should remove the namespace prefix even when it is different than the namespace in analysis.