Move widget.{get,set}_active to AxisWidget.

The method was previously defined only for RectangleSelectors (#3375).

Also, an redundant line was removed (RectangleSelectors are already set
active on __init__ by the superclass).
On 2014/08/17, 10:41 AM, Thomas A Caswell wrote:
> In lib/matplotlib/widgets.py:
>
>> @@ -111,6 +111,18 @@ def disconnect_events(self):
>>          for c in self.cids:
>>              self.canvas.mpl_disconnect(c)
>>
>> +    def set_active(self, active):
>> +        """Set whether the widget is active.
>> +        """
>> +        self._active = active
>> +
>> +    def get_active(self):
>> +        """Get whether the widget is active.
>> +        """
>> +        return self._active
>> +
>> +    active = property(set_active, get_active, doc="Is the widget active?")
>
> @mdboom <https://github.com/mdboom> @efiring
> <https://github.com/efiring> Do we have a style preference on using this
> method or the decorators?

I don't think this has been discussed.  The majority of existing 
properties use the function form.

Eric