Add namespae selection support to the cljs-in-cljs repl.
Implement CLJS-495 on the clojure version of the compiler by applying https://github.com/clojure/clojurescript/commit/3ee148acac436dd489396fc6783ba72bbd7ff79f -- on the cljs version, it's a defn that calls goog/typeOf.
Merge branch 'CLJS-495' into cljs_in_cljs