TypeError in SparseSeries.__repr__ when series longer than max_rows
``` python
In [2]: pd.__version__
Out[2]: '0.16.2-123-gdf1f5cf'

In [3]: pd.options.display.max_rows = 3

In [4]: pd.Series(randn(3)).to_sparse()
Out[4]: 
0    1.100684
1   -0.924482
2   -0.106069
dtype: float64
BlockIndex
Block locations: array([0], dtype=int32)
Block lengths: array([3], dtype=int32)

In [5]: pd.Series(randn(4)).to_sparse()
Out[5]: ---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
...
TypeError: cannot concatenate a non-NDFrame object
```

Set `max_rows=3` for demonstration, but occurs also for the default `max_rows=60`.
