Missing ellipsis cells in pivot_table.to_html when limited by max_cols and len(rows) > 1
``` python
import pandas
df = pandas.DataFrame([
    {'a': 'aa', 'b': 'ba', 'c': 'ca', 'd': 1},
    {'a': 'ab', 'b': 'bb', 'c': 'cc', 'd': 2},
    {'a': 'ac', 'b': 'bc', 'c': 'cc', 'd': 3}
])

df.pivot_table(cols=['a'], rows=['b', 'c']).to_html(max_cols=2)
```

This renders like this:
![broken_output](https://f.cloud.github.com/assets/1119169/2011357/c4149c0e-8779-11e3-952d-05499dd1e2e1.png)

while this:

``` python
df.pivot_table(cols=['a'], rows=['b']).to_html(max_cols=2)
```

renders like this:
![slection_656](https://f.cloud.github.com/assets/1119169/2011374/f7d9935a-8779-11e3-99c2-ddffa6537456.png)

As you can see in the first table, there are no ellipsis cells like in the second one.
I inspected the code to find the reason for this bug but couldn't find…
