Use Grimoire 0.4.6 /search

 - Remove (namespace version) case of cider-grimoire-url
 - Update cider-grimoire-url to use /search/v0 rather than full URL forging
 - Update test of cider-grimoire-url

Fixes #916 as clojurescript and clojure namespaces will both now search up
transparently without requiring plugin classpath introspection or anything else
crazy.