Do not close a popover when the mouse is hovering on it

Created by: abitdodgy

Since we can use HTML in a popover, it would be useful if the popover stayed opened when the mouse is hovering over it. This gives the user a chance to read something then click a link.

As it stands, the popover fades onMouseOut, or based on the delayOut argument. In order to use a link in the popover, we have to use a delayOut anyway to give the popover a chance to stay after onMouseOut.

But then the popover can disappear while hovering over the link.