CLJS-1467: Foreign Libraries not included when using :main with :simple or :advanced

Fixes bug by checking if either output-file or output-to option is
set, which means that compile-file will return a IJavaScript map instead
of a String when output-to option is set. Need to check if output-to is
a String, since it also could be the :print keyword, in which case we
don't want to write the output to disk.

Author: mneise

src/main/clojure/cljs/closure.clj

@@ -428,7 +428,7 @@
   returns a JavaScriptFile. In either case the return value satisfies
   IJavaScript."
   [^File file {:keys [output-file output-to] :as opts}]
-    (if output-file
+    (if (or output-file (string? output-to))
       (let [out-file (io/file (util/output-directory opts)
                        (or output-file output-to))]
         (compiled-file (comp/compile-file file out-file opts)))