Makes the game window active on mouse hover and inactive on mouse leave.
The Microsoft Flight Simulator game has non-standard mouse scrolling handling - the scrolling affects the game depending on whether the window is active or not, unlike other apps for which mouse scrolling works when the mouse is hovered over the window. This mod helps with this quirk by making the game window inactive when the mouse leaves it, so mouse scrolling no longer affects it, and by making the game window active when the mouse hovers over it, making mouse scrolling work again.