Till Death Etterna 0.58 Lag Test (boot and musicwheel)

[@xwidghet]

Looks like when image cache is on the theme's manual image displaying mixed with Stepmania's image caching is causing severe slowdown. Setting ImageCache=Off nets 550 fps in alphabetical sort with maximum speed tab scrolling. Guess a metric/theme setting should be added for "I'm going to manually display the images myself". Ex. EnableBannerCache=false, with default in fallback to true.