Series __finalized__ not correctly called in binary operators
```
#!/bin/env python
"""
Example bug in derived Pandas Series.

__finalized__ is not called in arithmetic binary operators, but it is in in some booleans cases.

>>> m = MySeries([1, 2, 3], name='test')
>>> m.x = 42
>>> n=m[:2]
>>> n
0    1
1    2
dtype: int64
>>> n.x
42
>>> o=n+1
>>> o
0    2
1    3
dtype: int64
>>> o.x
Traceback (most recent call last):
        ...
AttributeError: 'MySeries' object has no attribute 'x'
>>> m = MySeries([True, False, True], name='test2')
>>> m.x = 42
>>> n=m[:2]
>>> n
0     True
1    False
dtype: bool
>>> n.x
42
>>> o=n ^ True
>>> o
0    False
1     True
dtype: bool
>>> o.x
42
>>> p = n ^ o
>>> p
0    True
1    True
dtype: bool
>>> p.x
42

"""

import pandas as pd

class MySeries(pd.Series):
    _metadata = ['x']

    @property
    def _constructor(self):
        return MySeries

if __name__ == "__main__":
    import doctest
    doctest.testmod()

```
#### Expected Output

In all cases, the metadata 'x' should be transferred from the passed values when applying binary operators.
When the right-hand value is a constant, the left-hand value metadata should be used in **finalize** for arithmetic operators, just like it is for Boolean binary operators.
When two series are used in binary operators, some resolution should be possible in **finalize**.
I would pass the second (right-hand) value by calling **finalize**(self, other=other), leaving the resolution to the derived class implementer, but there might be a smarter approach.
#### output of `pd.show_versions()`

pd.show_versions()
## INSTALLED VERSIONS

commit: None
python: 2.7.6.final.0
python-bits: 64
OS: Linux
OS-release: 3.19.0-59-generic
machine: x86_64
processor: x86_64
byteorder: little
LC_ALL: None
LANG: en_US.UTF-8

pandas: 0.18.1
nose: 1.3.7
pip: None
setuptools: 20.2.2
Cython: 0.24
numpy: 1.11.0
scipy: 0.17.0
statsmodels: 0.6.1
xarray: None
IPython: 4.0.1
sphinx: 1.3.1
patsy: 0.4.0
dateutil: 2.4.2
pytz: 2015.7
blosc: None
bottleneck: 1.0.0
tables: 3.2.2
numexpr: 2.5.2
matplotlib: 1.5.0
openpyxl: 2.2.6
xlrd: 0.9.4
xlwt: 1.0.0
xlsxwriter: 0.7.7
lxml: 3.4.4
bs4: 4.4.1
html5lib: 0.9999999
httplib2: None
apiclient: None
sqlalchemy: 1.0.9
pymysql: None
psycopg2: None
jinja2: 2.8
boto: 2.38.0
pandas_datareader: None
