be80898 breaks display of large dataframes in IPython notebooks
In 044ee06, I could just do, with no apparent delay:

``` python
df
<class 'pandas.core.frame.DataFrame'>
Int64Index: 10718114 entries, 0 to 10718113
Columns: 20 entries, classification_id to spread
dtypes: datetime64[ns](2), float64(11), object(7)
```

In be80898, the notebook gets stuck and CPU is boiling and nothing is returned after 5 mins.

related #5550 
