Series.dot returns undocumented ndarray type
According to the documentation `pandas.Series.dot` returns a `pandas.Series` or a scalar value. Certainly, the output type is depending on the type and dimension of the first positional argument of the `pandas.Series.dot` function. The following example outputs a value of type `numpy.ndarray` using pandas (0.16.2):

``` python
In [0]: pd.Series(np.ones(3)).dot(np.eye(3))
out[0]: array([ 1.,  1.,  1.])
```

Even though, the result is plausible (array of scalars), the documentation is inconsistent on this. This only applies to `pandas.Series.dot`.
