Feature request

It would be nice if the user could toggle display of the legend (if any) in the figure options dialog box. Currently, it's possible to edit curve labels and regenerate the legend, but not toggle the display of the legend. This would be especially useful because sometimes the legend can obscure parts of the plot.

Apologies if this has been discussed somewhere already. I couldn't find anything here in GH issues.

Matplotlib version

• Operating system: Xubuntu 16.04
• Matplotlib version: 2.2.2, installed from pip
• Matplotlib backend (print(matplotlib.get_backend())): Qt5Agg
• Python version: 3.5.2
• Jupyter version (if applicable):
• Other libraries: