BUG(?): get default value doesn't work for Series
`Series` have a `get` method, but using the default value doesn't work for certain type combinations:

```
>>> s = pd.Series([1,2,3], index=["a","b","c"])
>>> s
a    1
b    2
c    3
dtype: int64
>>> s.get("d", 0)
0
>>> s.get(10, 0)
Traceback (most recent call last):
  File "<ipython-input-18-26d73ac73179>", line 1, in <module>
    s.get(10, 0)
  File "/usr/local/lib/python2.7/dist-packages/pandas-0.14.0_421_g20dfc6b-py2.7-linux-x86_64.egg/pandas/core/generic.py", line 1040, in get
    return self[key]
  File "/usr/local/lib/python2.7/dist-packages/pandas-0.14.0_421_g20dfc6b-py2.7-linux-x86_64.egg/pandas/core/series.py", line 484, in __getitem__
    result = self.index.get_value(self, key)
  File "/usr/local/lib/python2.7/dist-packages/pandas-0.14.0_421_g20dfc6b-py2.7-linux-x86_64.egg/pandas/core/index.py", line 1202, in get_value
    return tslib.get_value_box(s, key)
  File "tslib.pyx", line 540, in pandas.tslib.get_value_box (pandas/tslib.c:11831)
  File "tslib.pyx", line 555, in pandas.tslib.get_value_box (pandas/tslib.c:11678)
IndexError: index out of bounds
```

I'm not sure whether it makes the most sense just to teach `.get` to catch IndexErrors as well as KeyErrors and ValueErrors (which is what it does now), or whether a deeper change is warranted.
