API: Missing support for creating a DataFrame from Python native arrays (or other objects supporting the buffer protocol)
``` python
import pandas
import array

x=array.array('i', range(10))

pdf = pandas.DataFrame.from_items([('a', x)])
# fails with:
# ValueError: If use all scalar values, must pass index
```

Also, since x has a `__len__` may be the error message should not refer to a scalar.

Explicit casting to numpy arrays is a workaround, but it would seem convenient to have it done within the constructor for `DataFrame`:

``` python
import numpy
pdf = pandas.DataFrame.from_items([('a', numpy.asarray(x))])
```
