tools.tests.test_util:TestLocaleUtils.test_set_locale fails spuriously on FreeBSD
```
$ nosetests pandas.tools.tests.test_util:TestLocaleUtils.test_set_locale
F
======================================================================
FAIL: test_set_locale (pandas.tools.tests.test_util.TestLocaleUtils)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/obrienjw/src/github/pandas/pandas/tools/tests/test_util.py", line 71, in test_set_locale
    pass
  File "/home/obrienjw/src/github/pandas/pandas/util/testing.py", line 1308, in __exit__
    raise AssertionError("{0} not raised.".format(name))
AssertionError: Error not raised.

----------------------------------------------------------------------
Ran 1 test in 0.044s

FAILED (failures=1)
```

My environment:

```
$ git describe
v0.12.0-1110-gd250d64
$ ci/print_versions.py

INSTALLED VERSIONS
------------------
Python: 2.7.5.final.0
OS: FreeBSD 9.2-PRERELEASE FreeBSD 9.2-PRERELEASE #0 r254955: Tue Aug 27 11:01:00 EDT 2013     root@drivel.saltant.net:/usr/obj/usr/src/sys/NARB amd64
byteorder: little
LC_ALL: None
LANG: None

pandas: Not installed
Cython: 0.19.1
Numpy: 1.7.0
Scipy: 0.12.1
statsmodels: Not installed
    patsy: Not installed
scikits.timeseries: Not installed
dateutil: 2.1
pytz: 2013.8
bottleneck: Not installed
PyTables: Not Installed
    numexpr: 2.2.2
matplotlib: 1.2.0
openpyxl: Not installed
xlrd: Not installed
xlwt: Not installed
xlsxwriter: Not installed
sqlalchemy: Not installed
lxml: Not installed
bs4: Not installed
html5lib: Not installed
bigquery: Not installed
apiclient: Not installed
```

I will submit a pull request for this shortly.
