Update pandas/__init__.py
Removed try/except around import pandas.lib

The try/except hid a dateutil import error.

Wouldn't it be better to have the current exception?  Perhaps you can check for whether the `ImportError` came from `pandas` or not...
 IMO, it is better to not have any special handing of this import error, since the except block can raise an error with wrong information.

In my case, I didn't have python-dateutils in my virtual env. When doing "import pandas" I got the "C extensions not built" error, instead of "ImportError: No module named dateutil".
 I agree it would be preferable to have a better error message. Even checking explicitly for the presence of the .so/.pyd files (to determine whether the extensions have been built) would be better.
 I added a narrower check that will make dateutil import failures pass through, but still get a more helpful error message if the C extension isn't built at all
