fix for sound issue

rewinder sound issue
Merge branch 'SteelyWing-patch-2'
Cosmetic improvements
Reversed some config options
Fixed xBR filter not updating live
Added application icon
Zapper works in GUI mode
Fixed compiler warnings
Fixed save states on Windows
Fixed annoying segfault in libretro
Merge branch 'master' of git://github.com/libretro/nestopia