API/ENH: query an HDF5 store with a named index
from [SO](http://stackoverflow.com/questions/27354281/query-term-is-not-valid-condition-none/27356827#27356827)

```
In [1]: df = pd.DataFrame.from_dict({'A':[1,2],'B':[100,200], 'C':[42,11]})
In [2]: df_a = df.set_index('A')
In [3]: df_a
Out[3]: 
     B   C
A         
1  100  42
2  200  11

In [4]: store = pd.HDFStore('foo.h5','w')
In [5]: store.put('bar', df_a, format='table', data_columns=True)
In [7]: store.select('bar','index==1')
```

```
store.select('bar','A==1)
```

should work as well (obviously only for a named index)
