Printing a Series with dtype timedelta64
```
>>> import pandas as pd
>>> import numpy as np
>>> print pd.Series(np.array([1100, 20], dtype='timedelta64[s]'))
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Python27_64\lib\site-packages\pandas\core\series.py", line 911, in __str__
    return repr(self)
  File "C:\Python27_64\lib\site-packages\pandas\core\series.py", line 847, in __repr__
    name=True)
  File "C:\Python27_64\lib\site-packages\pandas\core\series.py", line 908, in _get_repr
    return formatter.to_string()
  File "C:\Python27_64\lib\site-packages\pandas\core\format.py", line 126, in to_string
    fmt_values = self._get_formatted_values()
  File "C:\Python27_64\lib\site-packages\pandas\core\format.py", line 117, in _get_formatted_values
    na_rep=self.na_rep)
  File "C:\Python27_64\lib\site-packages\pandas\core\format.py", line 691, in format_array
    return fmt_obj.get_result()
  File "C:\Python27_64\lib\site-packages\pandas\core\format.py", line 814, in get_result
    fmt_values = [formatter(x) for x in self.values]
  File "C:\Python27_64\lib\site-packages\pandas\core\format.py", line 812, in <lambda>
    formatter = lambda x: '% d' % x
TypeError: %d format: a number is required, not numpy.timedelta64
```

This is because timedelta64 is an int type (see format.format_array) but can't be formatted like that.
