ipython/ipython — pull request #7082 by minrk (2014-12-02 23:37:40+00:00)
Title: Warn about .py/.json collisions in config

when two versions of the config file set the same value, warn about clobbering, with a message, such as:

```
[TerminalIPythonApp] WARNING | Collisions detected in ipython_config.py and ipython_config.json config files. ipython_config.json has higher priority: {
"Klass": {
"trait": "'python' ignored, using 'json'"
}
}
```

In anticipation of more machine-written .json config