use when.js, do away with jQuery dependency

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "when"]
+	path = when
+	url = git://github.com/cujojs/when.git

src/autobahn.js

@@ -627,7 +627,7 @@ ab.Session.prototype.call = function () {
 
    var self = this;
 
-   var d = new $.Deferred();
+   var d = new when.defer();
    var callid;
    while (true) {
       callid = ab._newid();