Previously, the result could have been an instance of a subclass of int.

Also revert bpo-26202 and make attributes start, stop and step of the range
object having exact type int.

Add private function _PyNumber_Index() which preserves the old behavior
of PyNumber_Index() for performance to use it in the conversion functions
like PyLong_AsLong().

Copying property objects results in a TypeError. Steps to reproduce:

```
>>> import copy
>>> obj = property()
>>> copy.copy(obj)
````

This affects both shallow and deep copying.  
My idea for a fix is to add property objects to the list of "atomic" objects in the copy module.
These already include types like functions and type objects.

I also added property objects to the unit tests test_copy_atomic and test_deepcopy_atomic. This is my first PR, and it's highly likely I've made some mistake, so please be kind :)


https://bugs.python.org/issue38293

* When doing getattr lookups with a default of "None", it now
  uses an "is" comparison against None which is more correct
* Removed outdated code

Patch by Brandon Rhodes.

Optimized copying and deepcopying bytearrays, NotImplemented, slices,
short lists, tuples, dicts, sets.

non-atomic attributes.

supports copying of instances of classes whose __new__ method takes
keyword-only arguments.

Patch by Claudiu Popa.