allows the image link in the hoverlink setting to be displayed on top of an image when the mouse hovers over it.
the image that will be displayed when the mouse hovers over an image in the grid.
hoverimage is a true/false value and defaults to false
hoverlink defaults to featured-image-pro/img/magnify.png
In this example, the default hover image will display when your mouse hovers over an image in the grid.