Issue Opening Pre 0.12 Pickles Import Error
I am having an issue opening some old pickle files that I created a couple of years ago (July of 2014). These files were pickled using in the `cPickle` module in python and I am pretty sure using a version of pandas <=0.12. I was using `cPickle` to load the files and getting a `TypeError` until I found the following answers on stack overflow:

http://stackoverflow.com/questions/20444593/pandas-compiled-from-source-default-pickle-behavior-changed
http://stackoverflow.com/questions/27950991/pandas-backwards-compatibility-issue-with-pickle-0-14-1-and-0-15-2

The solution is to be to use `pd.read_pickle` to load these files instead of using the python module `cPickle`. However when I try using `pd.read_pickle` I get the following `ImportError`:

```python
---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
<ipython-input-8-451b9dbea93c> in <module>()
      1 data_dir="J:\Pat's Projects\Dynamical Phase Transition\Mosaic Trajectories"
      2 #fit_params=cPickle.load(open(data_dir+'circle_fitting_params_071614.pkl','r'))
----> 3 expt_data=pd.read_pickle(data_dir+'data_frames_071614.pkl')
      4 #expt_list=cPickle.load(open(data_dir+'expt_list_071614.pkl','r'))

C:\Users\Scherer Lab E\Anaconda2\envs\170112\lib\site-packages\pandas\io\pickle.pyc in read_pickle(path)
     63 
     64     try:
---> 65         return try_read(path)
     66     except:
     67         if PY3:

C:\Users\Scherer Lab E\Anaconda2\envs\170112\lib\site-packages\pandas\io\pickle.pyc in try_read(path, encoding)
     60             except:
     61                 with open(path, 'rb') as fh:
---> 62                     return pc.load(fh, encoding=encoding, compat=True)
     63 
     64     try:

C:\Users\Scherer Lab E\Anaconda2\envs\170112\lib\site-packages\pandas\compat\pickle_compat.pyc in load(fh, encoding, compat, is_verbose)
    115         up.is_verbose = is_verbose
    116 
--> 117         return up.load()
    118     except:
    119         raise

C:\Users\Scherer Lab E\Anaconda2\envs\170112\lib\pickle.pyc in load(self)
    862             while 1:
    863                 key = read(1)
--> 864                 dispatch[key](self)
    865         except _Stop, stopinst:
    866             return stopinst.value

C:\Users\Scherer Lab E\Anaconda2\envs\170112\lib\pickle.pyc in load_global(self)
   1094         module = self.readline()[:-1]
   1095         name = self.readline()[:-1]
-> 1096         klass = self.find_class(module, name)
   1097         self.append(klass)
   1098     dispatch[GLOBAL] = load_global

C:\Users\Scherer Lab E\Anaconda2\envs\170112\lib\pickle.pyc in find_class(self, module, name)
   1128     def find_class(self, module, name):
   1129         # Subclasses may override this
-> 1130         __import__(module)
   1131         mod = sys.modules[module]
   1132         klass = getattr(mod, name)

ImportError: No module named copy_reg
```

Like I said, I don't know exactly what version of pandas was used when these were pickled but I think it was <=0.12. I am using python 2.7 installed from the Anaconda distribution.

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

INSTALLED VERSIONS
------------------
commit: None
python: 2.7.12.final.0
python-bits: 64
OS: Windows
OS-release: 7
machine: AMD64
processor: Intel64 Family 6 Model 30 Stepping 5, GenuineIntel
byteorder: little
LC_ALL: None
LANG: None

pandas: 0.18.1
nose: 1.3.7
pip: 8.1.2
setuptools: 27.2.0
Cython: 0.24
numpy: 1.11.1
scipy: 0.17.1
statsmodels: None
xarray: None
IPython: 4.2.0
sphinx: 1.4.1
patsy: 0.4.1
dateutil: 2.5.3
pytz: 2016.4
blosc: None
bottleneck: 1.1.0
tables: 3.2.2
numexpr: 2.6.0
matplotlib: 2.0.0
openpyxl: 2.3.2
xlrd: 1.0.0
xlwt: 1.1.2
xlsxwriter: 0.9.2
lxml: 3.6.0
bs4: 4.4.1
html5lib: None
httplib2: None
apiclient: None
sqlalchemy: 1.0.13
pymysql: None
psycopg2: None
jinja2: 2.8
boto: 2.40.0
pandas_datareader: None