[STORM-239] Allow supervisor to operate in paths with spaces in them

Works around a bug in path-escaping for Resources, described here:
http://bugs.java.com/bugdatabase/view_bug.do?bug_id=4466485
Could do:
```Clojure
;; Work-around for JDK-4466485
uri (if-let [url-str (str (.getResource classloader RESOURCES-DIR))]
      (URI. url-str))
```

Then replace all `url` with `uri` below.