Reduce GET style error verbosity

package.json

@@ -23,7 +23,7 @@
         "node-varnish": "0.1.1",
         "underscore"  : "1.1.x",
         "grainstore"  : "~0.6.2",
-        "windshaft"  : "~0.4.14",
+        "windshaft"  : "~0.4.16",
         "step": "0.0.x",
         "generic-pool": "1.0.x",
         "redis": "0.7.2",

test/acceptance/server.js

@@ -56,6 +56,8 @@ suite('server', function() {
         }, function(res) {
           // FIXME: should be 401 Unauthorized
           assert.equal(res.statusCode, 500, res.body);
+          assert.deepEqual(JSON.parse(res.body),
+            {error: 'Sorry, you are unauthorized (permission denied)'});
           done();
         });
     });