Fix typos in notebooks

Addit'l errors were either uncaught or perhaps introduced in previous
commits. Thanks @sevyharris for catching these!

Author: jonwzheng

ipython/combustion_model_and_ignition_delay_demo.ipynb

@@ -423,8 +423,6 @@
     "network.advance(ign_delay_time)\n",
     "ROP_C = ct.ReactionPathDiagram(gas, 'C')\n",
     "\n",
-    "from PIL import Image as PILimg\n",
-    "ROP1 = plt.subplot(1,1,1)\n",
     "dot_file = os.path.join(directory, 'cantera', 'rxnpathC.dot')\n",
     "img_file = os.path.join(directory, 'cantera', 'rxnpathC.png')\n",
     "ROP_C.title = 'Reaction path diagram following C'\n",

ipython/temperature_dependent_solvation_free_energy.ipynb

@@ -94,15 +94,6 @@
     "## Run solvation calculations"
    ]
   },
-  {
-   "cell_type": "code",
-   "execution_count": null,
-   "metadata": {},
-   "outputs": [],
-   "source": [
-    "solvationDatabase.get_T_dep_solvation_energy_from_LSER_298(solute_data, solvent_data, T)"
-   ]
-  },
   {
    "cell_type": "code",
    "execution_count": null,