``Formatter.fix_minus``

`.Formatter.fix_minus` now performs hyphen-to-unicode-minus replacement

whenever :rc:`axes.unicode_minus` is True; i.e. its behavior matches the one

of ``.ScalarFormatter.fix_minus`` (`.ScalarFormatter` now just inherits that

implementation).

This replacement is now used by the ``format_data_short`` method of the various

builtin formatter classes, which affects the cursor value in the GUI toolbars.

``FigureCanvasBase`` now always has a ``manager`` attribute, which may be None

Previously, it did not necessarily have such an attribute. A check for

``hasattr(figure.canvas, "manager")`` should now be replaced by

``figure.canvas.manager is not None`` (or ``getattr(figure.canvas, "manager", None) is not None``

for back-compatibility).

``figure.add_axes()`` without arguments

Calling ``fig.add_axes()`` with no arguments currently does nothing. This call

will raise an error in the future. Adding a free-floating axes needs a position

rectangle. If you want a figure-filling single axes, use ``add_subplot()``

instead.

``backend_wx.DEBUG_MSG``

``backend_wx.DEBUG_MSG`` is deprecated. The wx backends now use regular

logging.