TestClipboard test failure on osx-64
I see the following:

```
======================================================================
ERROR: test_round_trip_frame (pandas.io.tests.test_clipboard.TestClipboard)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/Users/vagrant/src/master-env/lib/python2.7/site-packages/pandas/io/tests/test_clipboard.py", line 67, in test_round_trip_frame
    self.check_round_trip_frame(dt)
  File "/Users/vagrant/src/master-env/lib/python2.7/site-packages/pandas/io/tests/test_clipboard.py", line 54, in check_round_trip_frame
    result = read_clipboard()
  File "/Users/vagrant/src/master-env/lib/python2.7/site-packages/pandas/io/clipboard.py", line 32, in read_clipboard
    return read_table(StringIO(text), **kwargs)
  File "/Users/vagrant/src/master-env/lib/python2.7/site-packages/pandas/io/parsers.py", line 420, in parser_f
    return _read(filepath_or_buffer, kwds)
  File "/Users/vagrant/src/master-env/lib/python2.7/site-packages/pandas/io/parsers.py", line 218, in _read
    parser = TextFileReader(filepath_or_buffer, **kwds)
  File "/Users/vagrant/src/master-env/lib/python2.7/site-packages/pandas/io/parsers.py", line 502, in __init__
    self._make_engine(self.engine)
  File "/Users/vagrant/src/master-env/lib/python2.7/site-packages/pandas/io/parsers.py", line 616, in _make_engine
    self._engine = klass(self.f, **self.options)
  File "/Users/vagrant/src/master-env/lib/python2.7/site-packages/pandas/io/parsers.py", line 1303, in __init__
    self.columns, self.num_original_columns = self._infer_columns()
  File "/Users/vagrant/src/master-env/lib/python2.7/site-packages/pandas/io/parsers.py", line 1516, in _infer_columns
    line = self._buffered_line()
  File "/Users/vagrant/src/master-env/lib/python2.7/site-packages/pandas/io/parsers.py", line 1643, in _buffered_line
    return self._next_line()
  File "/Users/vagrant/src/master-env/lib/python2.7/site-packages/pandas/io/parsers.py", line 1659, in _next_line
    line = next(self.data)
  File "/Users/vagrant/src/master-env/lib/python2.7/site-packages/pandas/io/parsers.py", line 1420, in _read
    line = next(f)
StopIteration
```

With pandas 0.13.1 on os x (python 2.7.3, numpy 1.8.0, cython 0.19.2).
