[Feature Request] Zoom at point of mouse cursor

[yellek]

As a user when I zoom in I would like the centre of the zoomed in window to be where the mouse pointer is rather than the centre of the canvas.

This is a common feature in many other zoomable displays. Not a huge issue to work around with the navigation window or middle mouse button but it would be nice if what I was focussing on filled the screen when I zoom rather than the zoom going to a completely different part of the diagram.