ipython/ipython — pull request #4475 by Carreau (2013-11-01 15:54:41+00:00)
Title: %config --persist magic

Quick and dirty thing on top of
https://github.com/ipython/ipython/pull/4265 to have config magic write configuration to json file.
```
%config StoreMagics.autorestore= --persist
```

Will write to `ipython__config.json`, `None` as value will remove the value from the file.