regression in 0.10.1 with boolean indexing?
this used to work in 0.10 but now fails in 0.10.1:

```
import pandas
df = pandas.DataFrame(index=[1,2])
df['test'] = [1,2]
df['test'][[True, False]] = [0]
```

Now gives:
ValueError: Length of replacements must equal series length

possibly related to closed issue https://github.com/pydata/pandas/issues/2703
