Caching indicator icon when LaunchBox/BigBox is caching images

[Pacman56]

It would be nice if LaunchBox and BigBox displayed a caching indicator icon (very small icon) when background caching is taking place. In addition, when the user moves the mouse over this icon indicator in LaunchBox, the rom image being cached would be displayed. This would help the user know that when the indicator is displayed, they can expect the system to run slower and would also help confirm that images for the selected platform are being cached.