Dataframe isin2

Alternative (on top of) #4237

DataFrame isin method:

```
in [9]: df = pd.DataFrame([['a', 'a'], ['b', 'e'], ['c', 'f']], columns=['A', 'A'])

In [10]: df
Out[10]:
   A  A
0  a  a
1  b  e
2  c  f

In [11]: df.isin(['a'])
Out[11]:
       A      A
0   True   True
1  False  False
2  False  False

In [12]: df.isin({'A': ['a']})
Out[12]:
       A      A
0   True   True
1  False  False
2  False  False

In [13]: df.isin({0: ['a']}, iloc=True)
Out[13]:
       A      A
0   True  False
1  False  False
2  False  False
```