pytables interface does not provide kwargs to create_index at append
The following last lines from `_write_to_group()` from io/pytables.py show that kwargs are available but are not provided to create_index(). This prevents the user from creating a `kind='full'` index at `append` time:

``` python
s.write(obj = value, append=append, complib=complib, **kwargs)
        if s.is_table and index:
            s.create_index(columns = index)
```
