Deprecate Series.asobject, Index.asobject, rename to _asobject

[TomAugspurger]

In [13]: pd.Series.asobject?
Type:        property
String form: <property object at 0x10b674548>
Docstring:
return object Series which contains boxed values

*this is an internal non-public method*

Let's make it private then.

[jreback]

this is for compat with Index; should do the same there

we actually don’t need this method but that’s for another issue

[jorisvandenbossche]

Is the alternative to do astype(object) ?

+1 on deprecating