"'TableIterator' object is not an iterator" when calling df.read_hdf()
#### Code Sample, a copy-pastable example if possible

```python
reader = pd.read_hdf(filename, 'foo', chunksize=1000)
next(reader)
```
```python
TypeError: 'TableIterator' object is not an iterator
```
#### Problem description

Unless I'm missing something, I would expect something called `TableIterator` to be (itself) an iterator. Since this is an analog of `df.read_csv()`, I would expect it to behave along the same lines (which is `TextFileReader` and works with `next()`). 

`reader.__iter__()` is defined, so `for chunk in reader` works. It's just slightly surprising that `TextFileReader` defines `__next__()`, but TableIterator does not. 

#### Expected Output
`next(reader)` should give the dataframe corresponding to that chunk.

(yes I know Iterators and Iterables are slightly different, but in this case I would expect both to be supported)

#### Output of ``pd.show_versions()``

<details>

INSTALLED VERSIONS
------------------
commit: None
python: 3.5.2.final.0
python-bits: 64
OS: Linux
OS-release: 4.4.0-79-generic
machine: x86_64
processor: x86_64
byteorder: little
LC_ALL: None
LANG: en_US.UTF-8
LOCALE: en_US.UTF-8

pandas: 0.19.2
nose: None
pip: 9.0.1
setuptools: 36.0.1
Cython: None
numpy: 1.12.1
scipy: 0.19.0
statsmodels: None
xarray: None
IPython: 6.1.0
sphinx: None
patsy: None
dateutil: 2.6.0
pytz: 2016.10
blosc: None
bottleneck: None
tables: 3.4.2
numexpr: 2.6.2
matplotlib: 2.0.0
openpyxl: None
xlrd: None
xlwt: None
xlsxwriter: None
lxml: None
bs4: 4.5.3
html5lib: 0.999999999
httplib2: None
apiclient: None
sqlalchemy: None
pymysql: None
psycopg2: None
jinja2: 2.9.6
boto: None
pandas_datareader: None

</details>
