add toolbar highlighting on hover

examples/notebooks/Part 1 - Running Code.ipynb

@@ -34,7 +34,18 b''
      "cell_type": "markdown",
      "metadata": {},
      "source": [
-      "Run a code cell using `Shift-Enter` or pressing the <button><i class=\"icon-play\" /></button> button in the toolbar above:"
+      "\n",
+      "<script type=\"text/javascript\">\n",
+      "var _toggle=false;\n",
+      "var hl = function (id, on){\n",
+      "    $(id)[0].style.background = '';\n",
+      "    if (on) {\n",
+      "        $(id)[0].style.background = 'gold';\n",
+      "    }\n",
+      "};\n",
+      "</script>\n",
+      "\n",
+      "Run a code cell using `Shift-Enter` or pressing the <button><i class=\"icon-play\" /></button> button in the <a href=\"#\" onMouseover=\"hl('#maintoolbar-container', 1)\" onMouseout=\"hl('#maintoolbar-container', 0)\">toolbar</a> above:"
      ]
     },
     {
@@ -79,7 +90,7 b''
      "cell_type": "markdown",
      "metadata": {},
      "source": [
-      "Code is run in a separate process called the IPython Kernel.  The Kernel can be interrupted or restarted.  Try running the following cell and then hit the <button><i class='icon-stop'/></button> button in the toolbar above."
+      "Code is run in a separate process called the IPython Kernel.  The Kernel can be interrupted or restarted.  Try running the following cell and then hit the <button><i class='icon-stop'/></button> button in the <a href=\"#\" onMouseover=\"hl('#maintoolbar-container', 1)\" onMouseout=\"hl('#maintoolbar-container', 0)\">toolbar</a> above."
      ]
     },
     {