Import @edsu's fix for the jsChannel vs Prototype problem

Updated jsChannel to this version:
https://github.com/edsu/jschannel/tree/e9caa88ac9390385b57d263528f0869ae6a48ac9

Fixes #608.

h/lib/jschannel.js

@@ -233,6 +233,21 @@
             if (!window.JSON || !window.JSON.stringify || ! window.JSON.parse) {
                 throw("jschannel cannot run this browser, no JSON parsing/serialization");
             }
+            if (window.Prototype) {
+                // Some versions of Prototype ship with a broken Array.toJSON
+                // which flattens arrays into strings! Since we have a working
+                // JSON.stringify we can safely remove it.
+                // See: http://stackoverflow.com/questions/710586/json-stringify-bizarreness
+                console.log("patching Prototype's faulty Array.toJSON")
+                var stringify = window.JSON.stringify;
+                window.JSON.stringify = function(value) {
+                    var _array_tojson = Array.prototype.toJSON;
+                    delete Array.prototype.toJSON;
+                    var r = stringify(value);
+                    Array.prototype.toJSON = _array_tojson;
+                    return r;
+                }
+            }
 
             /* basic argument validation */
             if (typeof cfg != 'object') throw("Channel build invoked without a proper object argument");
@@ -544,8 +559,14 @@
                     // object and pick out all of the functions that were passed as arguments.
                     var callbacks = { };
                     var callbackNames = [ ];
+                    var seen = [ ];
 
                     var pruneFunctions = function (path, obj) {
+                        if (seen.indexOf(obj) >= 0) {
+                            throw "params cannot be a recursive data structure"
+                        }
+                        seen.push(obj);
+
                         if (typeof obj === 'object') {
                             for (var k in obj) {
                                 if (!obj.hasOwnProperty(k)) continue;