Rework addition of Symbian splash screen to reduce the source impact (uses SVG from Bug 2414) Notes: by using the OPTION SOURCEDIR parameter in the mifconv extension instructions, I can arrange to use the same source file name in sfimage, without having to export over the original Nokia file. This means that the name inside splashscreen.mbg is the same, which removes the need for the conditional compilation in SplashScreen.cpp, and gets rid of sf_splashscreen.mmp.