BUG: Make sure series-series boolean comparions are label based (GH4947)
closes #4947

You ask for a boolean comparsion, that is what you get

```
In [1]: a = Series([True, False, True], list('bca'))

In [2]: b = Series([False, True, False], list('abc'))

In [19]: a
Out[19]: 
b     True
c    False
a     True
dtype: bool

In [20]: b
Out[20]: 
a    False
b     True
c    False
dtype: bool

In [21]: a & b
Out[21]: 
b     True
c    False
a    False
dtype: bool

In [22]: a | b
Out[22]: 
b     True
c    False
a     True
dtype: bool

In [23]: a ^ b
Out[23]: 
b    False
c    False
a     True
dtype: bool

In [24]: a & Series([])
Out[24]: 
b    False
c    False
a    False
dtype: bool

In [25]: a | Series([])
Out[25]: 
b     True
c    False
a     True
dtype: bool
```

these ok?

```
In [9]: Series([np.nan,np.nan])&Series([np.nan,np.nan])
Out[9]: 
0    False
1    False
dtype: bool

In [10]: Series([np.nan,np.nan])|Series([np.nan,np.nan])
Out[10]: 
0    False
1    False
dtype: bool
```

scalars

```

In [30]: a | True
Out[30]: 
b    True
c    True
a    True
dtype: bool

In [31]: a | False
Out[31]: 
b     True
c    False
a     True
dtype: bool

In [32]: a & True
Out[32]: 
b     True
c    False
a     True
dtype: bool

In [33]: a & False
Out[33]: 
b    False
c    False
a    False
dtype: bool
```

Invalid scalars

```
In [28]: a | 'foo'
TypeError: cannot compare a dtyped [bool] array with a scalar of type [bool]

In [29]: a | np.nan
TypeError: cannot compare a dtyped [bool] array with a scalar of type [float]
```
