BUG: wrong detection if truncated repr is needed
There seems to be a bug in the detection of when a DataFrame repr will not fit the console width.

Small example, the repr of a 7 column float dataframe is 72 characters wide:

```
In [10]: pd.DataFrame(np.random.randn(3, 7))
Out[10]: 
          0         1         2         3         4         5         6
0 -0.039631 -0.630607 -0.041318 -0.679839  0.257494 -0.608414  0.013959
1  0.976692  0.578279  0.712098  1.292541 -0.934307  0.522638 -0.584541
2 -1.218953  0.124633 -0.705128  0.376275  0.044354  0.166730  1.122929
```

However, in my default terminal of 80 characters wide, it is truncated:

```
In [1]: pd.io.formats.console.get_terminal_size()
Out[1]: os.terminal_size(columns=80, lines=24)

In [2]: pd.DataFrame(np.random.randn(3, 7))
Out[2]: 
          0         1         2    ...            4         5         6
0  0.332255  0.408991 -0.446875    ...     0.533822  0.128198  0.421326
1  0.335729 -0.889485  2.038889    ...    -0.263465  1.786649  1.190037
2  0.197376  1.742540 -1.259510    ...     0.643844  0.634065 -0.623578

[3 rows x 7 columns]
```

("funny" thing is that this truncated repr is actually exactly as wide as the non-truncated one ...)