deepcopy failure on empty dataframes with non-empty column set (numpy 1.12 compatibility)
#### Code Sample, a copy-pastable example if possible

```python
# Your code here
import pandas as pd
import copy

# This one works
df = pd.DataFrame(data=[], index=[])
df_copy = copy.deepcopy(df)

# This one fails
df2 = pd.DataFrame(data=[], index=[], columns=['a'])
df2_copy = copy.deepcopy(df2)
```
#### Problem description

This only occurs with numpy 1.12 (and, presumably above): when deepcopying an empty dataframe with a non-empty column set, it fails with the following:

```
ValueError: Iteration of zero-sized operands is not enabled
```

If the column set is also empty, everything works as expected.

On older numpy versions (1.11), it also works as expected.

#### Expected Output

Not failing.

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

<details>
# Paste the output here pd.show_versions() here
INSTALLED VERSIONS
------------------
commit: None
python: 3.4.0.final.0
python-bits: 64
OS: Linux
OS-release: 4.4.0-62-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: 1.3.7
pip: 9.0.1
setuptools: 32.3.1.post20170108
Cython: 0.25.2
numpy: 1.12.0
scipy: 0.18.1
statsmodels: None
xarray: None
IPython: 5.1.0
sphinx: None
patsy: None
dateutil: 2.6.0
pytz: 2016.10
blosc: None
bottleneck: None
tables: None
numexpr: None
matplotlib: 2.0.0
openpyxl: None
xlrd: None
xlwt: None
xlsxwriter: None
lxml: None
bs4: None
html5lib: None
httplib2: None
apiclient: None
sqlalchemy: None
pymysql: None
psycopg2: None
jinja2: None
boto: None
pandas_datareader: None
</details>
