FIX? df.__repr__ takes for ever with big data
Hi all, 

after having updated my local branch with the current dev master ( pd.**version** == '0.11.0rc1' -- compiling under Mac OS 10.8 went smoothly) some of my scripts in which I handle large data frames (2.6 million rows, 10 columns) stopped working. 
It turned out that accessing the df's repr method but also looking up docstrings seems to make ipython unresponsive and creates the impression as if it takes forever.

This little snippet reproduces the error with fake data ('tested' with EPD Python and IPython 7.2 (32-bit)):

``` Python
import numpy as np
import pandas as pd

data  = np.random.random((3000000, 10))
df = pd.DataFrame(data)

print df  # does the same as `df.__repr__()` or `df?`
```

Can anyone confirm this?
It must have been some of the more recent changes as I did not have trouble with this earlier.
Any pointers and comments are highly welcome.

Cheers,
Denis
