Please add ability to zoom with mouse

Please add ability to zoom with mouse

Right now, as far as I can tell, you can zoom in/out using the slider at the bottom.  When the image is zoomed in, the image moves vertically while scrolling and horizontally when holding down the shift key while scrolling.  Please use the mouse wheel/scroll to control zoom functions.  You can already move the image by dragging the mouse while holding down the left button. 

Thanks.