Revamp the EMF namespace.

Renamed several functions.  Now there are no wrappers for Ecore and
normal EMF models anymore, but you work with standard EMF resources.

Also revamped EMF type specs which can now disambiguate even if there
are multiple EClassifiers with identical qnames (but in packages with
different nsURIs).  Such type specs can look like:

  {"http://foo/1.0" 'pkg.SomeClass}  ;; Version 1.0 of SomeClass
  {"http://foo/1.1" 'pkg.SomeClass}  ;; Version 1.1 of SomeClass

Nesting and with complex type specs is also possible:

  {"http://foo/1.0"
   [:or 'SomeClass 'SomeOtherClass
    {"http://foo/1.1"
     [:or 'SomeClass 'SomeOtherClass]}]}

equiv to:

  [:or {"http://foo/1.0" [:or 'SomeClass 'SomeOtherClass]}
       {"http://foo/1.1" [:or 'SomeClass 'SomeOtherClass]}]