Fixing minor bugs in nbformat and saving.

* json separator is not ',' to avoid adding extra space at EOL.
* vs used throughout nbformat.current.
* Cell collapse is properly loaded from notebook.

IPython/frontend/html/notebook/static/js/codecell.js

@@ -824,6 +824,8 @@ var IPython = (function (IPython) {
             if (data.collapsed !== undefined) {
                 if (data.collapsed) {
                     this.collapse();
+                } else {
+                    this.expand();
                 };
             };
         };

IPython/frontend/html/notebook/static/js/notebook.js

@@ -1191,7 +1191,7 @@ var IPython = (function (IPython) {
         // We may want to move the name/id/nbformat logic inside toJSON?
         var data = this.toJSON();
         data.metadata.name = nbname;
-        data.nbformat = 2;
+        data.nbformat = 3;
         // We do the call with settings so we can set cache to false.
         var settings = {
             processData : false,

IPython/frontend/html/notebook/static/js/quickhelp.js

@@ -42,6 +42,7 @@ var IPython = (function (IPython) {
             {key: 'Ctrl-m y', help: 'code cell'},
             {key: 'Ctrl-m m', help: 'markdown cell'},
             {key: 'Ctrl-m t', help: 'plaintext cell'},
+            {key: 'Ctrl-m 1-6', help: 'heading 1-6 cell'},
             {key: 'Ctrl-m p', help: 'select previous'},
             {key: 'Ctrl-m n', help: 'select next'},
             {key: 'Ctrl-m i', help: 'interrupt kernel'},