Combined value_counts()
Rather often, especially when exploring the data or creating reports, one is interested both in `pd.Series.value_counts()` and `pd.Series.value_counts(normalize=True). I prepared a branch which implements a wrapper which takes care of this ([link](https://github.com/drorata/pandas/tree/dual_value_counts))

- Does it make sense?
- Is this implementation meeting pandas' standards?
- Should testing of this simple wrapper be extended?

