HTML rendering of dataframes no longer working
#### Code Sample, a copy-pastable example if possible

```python
import numpy as np
import pandas as pd
arrays = [np.hstack([ ['one']*3, ['two']*3]), ['Dog', 'Bird', 'Cat']*2]
columns = pd.MultiIndex.from_arrays(arrays, names=['foo', 'bar'])
df = pd.DataFrame(np.zeros((3,6)),columns=columns,index=pd.date_range('20000103',periods=3))
df
```
#### Problem description
The HTML table of a dataframe is no longer rendering in the most recent versions. I am not sure if this is an issue that should be solved in Pandas or IPython but the symptom is in pandas. The shortest way to a reproduction of the issues is to install a fresh build of Canopy and run the above code. I have talked with the Canopy people and they have desire to see this fixed but no bandwidth to do it themselves. Some more info is on the related stack overflow question http://stackoverflow.com/questions/37041696/html-not-rendering-properly-with-canopy-1-7-1-3323-ipython-4-1-2


