Remove cells.

examples/introduction.ipynb

 {
  "metadata": {
   "name": "",
-  "signature": "sha256:1f4a71e4b75cc1f61fe31b06e7896548a61c21374da560610a923999cf0800f6"
+  "signature": "sha256:668cc72f84bf7467ee8cfef29fc14ef9cd1fd272e3352c5152ded54490865f5e"
  },
  "nbformat": 3,
  "nbformat_minor": 0,
@@ -212,7 +212,7 @@
      "cell_type": "markdown",
      "metadata": {},
      "source": [
-      "You can't read from or write to a closed dataset, but you"
+      "You can't read from or write to a closed dataset, but you can access its properties."
      ]
     },
     {
@@ -235,72 +235,6 @@
      ],
      "prompt_number": 23
     },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "with rasterio.drivers(CPL_DEBUG=True):\n",
-      "\n",
-      "    # Read raster bands directly to Numpy arrays.\n",
-      "    with rasterio.open('../tests/data/RGB.byte.tif') as src:\n",
-      "        r, g, b = src.read()\n",
-      "\n",
-      "    # Combine arrays using the 'iadd' ufunc. Expecting that the sum will\n",
-      "    # exceed the 8-bit integer range, initialize it as 16-bit. Adding other\n",
-      "    # arrays to it in-place converts those arrays up and preserves the type\n",
-      "    # of the total array.\n",
-      "    total = np.zeros(r.shape, dtype=rasterio.uint16)\n",
-      "    for band in (r, g, b):\n",
-      "        total += band\n",
-      "    total /= 3\n",
-      "\n",
-      "    # Write the product as a raster band to a new 8-bit file. For keyword\n",
-      "    # arguments, we start with the meta attributes of the source file, but\n",
-      "    # then change the band count to 1, set the dtype to uint8, and specify\n",
-      "    # LZW compression.\n",
-      "    kwds = src.meta\n",
-      "    kwds.update(\n",
-      "        dtype=rasterio.uint8,\n",
-      "        count=1,\n",
-      "        compress='lzw')\n",
-      "\n",
-      "    with rasterio.open('output.tif', 'w', **kwds) as dst:\n",
-      "        dst.write_band(1, total.astype(rasterio.uint8))"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [],
-     "prompt_number": 9
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "%matplotlib inline"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": [],
-     "prompt_number": 8
-    },
-    {
-     "cell_type": "code",
-     "collapsed": false,
-     "input": [
-      "import matplotlib.pyplot as plt"
-     ],
-     "language": "python",
-     "metadata": {},
-     "outputs": []
-    },
     {
      "cell_type": "markdown",
      "metadata": {},