Handling for FixedOffsetTimezone in tseries/tools.py
**Version:** 0.9.0.dev e98a568-py2.7-macosx-10.6-x86_64

When passing a string column with timestamps like `"2012-04-23 10:00:23.123000-07:00"` (fixed offset timezone) to DataFrame.set_index() ,  getting exception:

**AttributeError: 'FixedOffsetTimezone' object has no attribute 'zone'**

```
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-4-d8465aa13e80> in <module>()
----> 1 df.set_index('ts')

/Users/redacted/.pythonbrew/venvs/Python-2.7.3/redacted/lib/python2.7/site-packages/pandas-0.9.0.dev_e98a568-py2.7-macosx-10.6-x86_64.egg/pandas/core/frame.pyc in set_index(self, keys, drop, append, inplace, verify_integrity)
   2422             arrays.append(level)
   2423 
-> 2424         index = MultiIndex.from_arrays(arrays, names=names)
   2425 
   2426         if verify_integrity and not index.is_unique:

/Users/redacted/.pythonbrew/venvs/Python-2.7.3/redacted/lib/python2.7/site-packages/pandas-0.9.0.dev_e98a568-py2.7-macosx-10.6-x86_64.egg/pandas/core/index.pyc in from_arrays(cls, arrays, sortorder, names)
   1551         if len(arrays) == 1:
   1552             name = None if names is None else names[0]
-> 1553             return Index(arrays[0], name=name)
   1554 
   1555         cats = [Categorical.from_array(arr) for arr in arrays]

/Users/redacted/.pythonbrew/venvs/Python-2.7.3/redacted/lib/python2.7/site-packages/pandas-0.9.0.dev_e98a568-py2.7-macosx-10.6-x86_64.egg/pandas/core/index.pyc in __new__(cls, data, dtype, copy, name)
    109             if _shouldbe_timestamp(subarr):
    110                 from pandas.tseries.index import DatetimeIndex
--> 111                 return DatetimeIndex(subarr, copy=copy, name=name)
    112 
    113             if lib.is_period_array(subarr):

/Users/redacted/.pythonbrew/venvs/Python-2.7.3/redacted/lib/python2.7/site-packages/pandas-0.9.0.dev_e98a568-py2.7-macosx-10.6-x86_64.egg/pandas/tseries/index.pyc in __new__(cls, data, freq, start, end, periods, copy, name, tz, verify_integrity, normalize, **kwds)
    228         else:
    229             try:
--> 230                 subarr = tools.to_datetime(data)
    231             except ValueError:
    232                 # tz aware

/Users/redacted/.pythonbrew/venvs/Python-2.7.3/redacted/lib/python2.7/site-packages/pandas-0.9.0.dev_e98a568-py2.7-macosx-10.6-x86_64.egg/pandas/tseries/tools.pyc in to_datetime(arg, errors, dayfirst, utc, box)
     90         if isinstance(arg, list):
     91             arg = np.array(arg, dtype='O')
---> 92         result = _convert_f(arg)
     93         return result
     94     try:

/Users/redacted/.pythonbrew/venvs/Python-2.7.3/redacted/lib/python2.7/site-packages/pandas-0.9.0.dev_e98a568-py2.7-macosx-10.6-x86_64.egg/pandas/tseries/tools.pyc in _convert_f(arg)
     75         except ValueError, e:
     76             try:
---> 77                 values, tz = lib.datetime_to_datetime64(arg)
     78                 return DatetimeIndex._simple_new(values, None, tz=tz)
     79             except (ValueError, TypeError):

/Users/redacted/.pythonbrew/venvs/Python-2.7.3/redacted/lib/python2.7/site-packages/pandas-0.9.0.dev_e98a568-py2.7-macosx-10.6-x86_64.egg/pandas/lib.so in pandas.lib.datetime_to_datetime64 (pandas/src/tseries.c:38359)()

/Users/redacted/.pythonbrew/venvs/Python-2.7.3/redacted/lib/python2.7/site-packages/pandas-0.9.0.dev_e98a568-py2.7-macosx-10.6-x86_64.egg/pandas/lib.so in pandas.lib._get_zone (pandas/src/tseries.c:37262)()

AttributeError: 'FixedOffsetTimezone' object has no attribute 'zone'

```

As an aside, I believe this is a common tz-aware timestamp for Postgres, so encountering this with:

`df = pd.io.sql.frame_query(QRY, con=_engine.raw_connection(), index_col='ts')`

```
```
