Master branch not building with Python 3
I tried building the master branch with python 3.2.2 and cython-0.15.1 and ran into a couple problems.

First, the compile failed because of the deprecated "basetring" used on line 48 of pandas/src/datetime.pyx.

After fixing that, pandas built, but failed when I tried to import it:

```
---------------------------------------------------------------------------
ImportError                               Traceback (most recent call last)
/home/emarkley/tmp/<ipython-input-1-d6ac987968b6> in <module>()
----> 1 import pandas

/usr/local/lib/python3.2/site-packages/pandas-0.8.0.dev-py3.2-linux-x86_64.egg/pandas/__init__.py in <module>()
      8
      9 try:
---> 10     import pandas._tseries as lib
     11 except Exception as e:  # pragma: no cover
     12     if 'No module named' in str(e):

ImportError: /usr/local/lib/python3.2/site-packages/pandas-0.8.0.dev-py3.2-linux-x86_64.egg/pandas/_tseries.cpython-32m.so: undefined symbol: PyInt_AsLong
```
