.loc for appending/assigning multiple values
According to the latest v0.13 docs `.loc` can append, but can it (or rather, should it?) append more than one value at once?

**Setting multiple via .loc:**

``` python
>>> df = pd.DataFrame(columns=['x', 'y'])
>>> df.loc[:, 'x'] = [1, 2]
>>> df
Empty DataFrame
Columns: [x, y]
Index: []
>>> df.loc[[0, 1], 'x'] = [1, 2]
>>> df
Empty DataFrame
Columns: [x, y]
Index: []
>>> df.loc[0:2, 'x'] = [1, 2]
>>> df
Empty DataFrame
Columns: [x, y]
Index: []
```

**Setting single via .loc:** (works as intended)

``` python
>>> df = pd.DataFrame(columns=['x', 'y'])
>>> df.loc[0, 'x'] = 1
>>> df
   x    y
0  1  NaN
```
