ipython loses auto-show/auto-redraw behavior after call to `plt.rcdefaults()`

matplotlib 2.0b4, ipython 5.1.0, python 3.5.2.

After calling `plt.rcdefaults()` in an ipython session, plotting commands (e.g. `plt.plot([1, 2])`) do not auto-show/auto-redraw the figure anymore (explicit calls to `plt.show()`/`fig.canvas.draw()` becomes needed).  It would certainly be better if the auto-show/auto-redraw behavior was kept.
