- Use
[MPLBACKEND](http://matplotlib.org/devel/coding_guide.html?highlight=mplbackend#developing-a-new-backend)
environment variable to tell matplotlib >= 1.5 use use the inline
backend by default. This is only done if MPLBACKEND is not already
set and no backend has been explicitly loaded, so setting
`MPLBACKEND=Qt4Agg` or calling `%matplotlib notebook` or
`matplotlib.use('Agg')` will take precedence.
- Fixes for logging problems caused by 4.3, where logging could go to
the terminal instead of the notebook.
- Add `--sys-prefix` and `--profile` arguments to
`ipython kernel install`.
- Allow Comm (Widget) messages to be sent from background threads.
- Select inline matplotlib backend by default if `%matplotlib` magic
or `matplotlib.use()` are not called explicitly (for matplotlib >=
1.5).
- Fix some longstanding minor deviations from the message protocol
(missing status: ok in a few replies, connect_reply format).
- Remove calls to NoOpContext from IPython, deprecated in 5.0.