fix event hookup for kernel changed

event is kernel_created.Session

The spec name on the kernel also wasn't being changed when the kernel changed.

IPython/html/static/notebook/js/kernelselector.js

@@ -76,12 +76,12 @@ define([
             that.element.find("#current_kernel_spec").find('.kernel_name').text(data.display_name);
         });
         
-        this.events.on('started.Session', function(events, session) {
-            if (session.kernel_name !== that.current_selection) {
+        this.events.on('kernel_created.Session', function(event, data) {
+            if (data.kernel.name !== that.current_selection) {
                 // If we created a 'python' session, we only know if it's Python
                 // 3 or 2 on the server's reply, so we fire the event again to
                 // set things up.
-                var ks = that.kernelspecs[session.kernel_name];
+                var ks = that.kernelspecs[data.kernel.name];
                 that.events.trigger('spec_changed.Kernel', ks);
             }
         });

IPython/html/static/services/sessions/session.js

@@ -97,7 +97,9 @@ define([
     Session.prototype.start = function (success, error) {
         var that = this;
         var on_success = function (data, status, xhr) {
-            if (!that.kernel) {
+            if (that.kernel) {
+                that.kernel.name = that.kernel_model.name;
+            } else {
                 var kernel_service_url = utils.url_path_join(that.base_url, "api/kernels");
                 that.kernel = new kernel.Kernel(kernel_service_url, that.ws_url, that.notebook, that.kernel_model.name);
             }