[issue25564] Document that IDLE behaves differently than python on `del __builtins__`

[ppperry]

Changes by ppperry <mapreader at olum.org>:


----------
title: IDLE behaves differently than python on `del __builtins__` -> Document that IDLE behaves differently than python on `del __builtins__`

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue25564>
_______________________________________