not dismiss while mouseover

While mouse is hovering over the growl box, the growl box will not fade out after it is initial delay set in the "options".

Instead, if the time of mouse hovering over on the growl box is longer than  or equal to the initial delay, it will fade out at once after the mouse leaves the growl box. Otherwise, it will fade out after the period (initial delay minus the time of mouse hovering) after the mouse leaves.