BUG: tz in index not working in HDFStore with table
```
In [1]: df = DataFrame(dict(A = Series(xrange(3), index=date_range('2000-1-1',periods=3,freq='H', tz='US/Eastern'))))

In [2]: df.index
Out[2]: 
<class 'pandas.tseries.index.DatetimeIndex'>
[2000-01-01 00:00:00, ..., 2000-01-01 02:00:00]
Length: 3, Freq: H, Timezone: US/Eastern

In [3]: df.to_hdf('tz.h5','df',mode='w')

In [4]: pd.read_hdf('tz.h5','df').index
Out[4]: 
<class 'pandas.tseries.index.DatetimeIndex'>
[2000-01-01 00:00:00, ..., 2000-01-01 02:00:00]
Length: 3, Freq: H, Timezone: US/Eastern

In [5]: df.to_hdf('tz.h5','df',mode='w',table=True)

In [6]: pd.read_hdf('tz.h5','df').index
Out[6]: 
<class 'pandas.tseries.index.DatetimeIndex'>
[2000-01-01 00:00:00, ..., 2000-01-01 02:00:00]
Length: 3, Freq: H, Timezone: US/Eastern
```
