Issue #17098: Make sure every module has __loader__ defined.

Thanks to Thomas Heller for the bug report.
Issue #17098: all modules should have __loader__
Fixes Issue #6972: The zipfile module no longer overwrites files outside of
its destination path when extracting malicious zip files.
Fixes Issue #6972: The zipfile module no longer overwrites files outside of
its destination path when extracting malicious zip files.
Fixes Issue #6972: The zipfile module no longer overwrites files outside of
its destination path when extracting malicious zip files.
Add a test for fix of issue #17098
merge with 3.3
Issue #17098: Be more stringent of setting __loader__ on early imported
modules. Also made test more rigorous.
Additional fix for Issue #12268: The io module file object writelines() methods no longer abort early when one of its write system calls is interrupted (EINTR).
better corrected news entry
Additional fix for issue #12268: The io module file object write methods no
longer abort early when a write system call is interrupted (EINTR).
null merge
Additional fix for issue #12268: The io module file object write methods no
longer abort early when a write system call is interrupted (EINTR).
Merge w/ 3.3 more fixes thanks to issue #17098
merge
merge
merge from 3.3
Issue #16256: OS X installer now sets correct permissions for doc directory.
Issue #16256: merge from 3.2
Issue #16256: merge from 3.3