fix create sign for urls containing spechial chars: !'()#*+? and non latin chars

Author: victornikitin

lib/client.js

@@ -854,7 +854,7 @@ Client.prototype.https = function(filename){
 
 Client.prototype.signedUrl = function(filename, expiration, options){
   var epoch = Math.floor(expiration.getTime()/1000)
-    , pathname = url.parse(filename).pathname
+    , pathname = url.parse(encodeSpecialCharacters(filename)).pathname
     , resource = '/' + this.bucket + ensureLeadingSlash(pathname);
 
   if (options && options.qs) {