Redo/undo buttons for widget

[YooSunYoung]

Especially for zooming in/out, it's often cumbersome to use home button and redo all the zooming again... cause you have to be very careful not to mess up again.

@bingli621 suggested

[nvaytet]

So basically you would like to have the matplotlib buttons for 'previous view' and 'next view'? (the left and right arrows)

[bingli621]

Yes, that's exactly what's needed here.

[nvaytet]

Now that we have freed-up space by moving the log buttons onto the axes, maybe we can add them back in?