ReplayGain Scan macOS Catalina support

I've finally updated the Replay Gain scan utility to be 64-bit, thanks to an update of the program I use to package and run the scripts (Platypus). It should now run fine on macOS Catalina 10.15, but I can't confirm that as I've yet to upgrade. (I don't want to lose my old 32-bit games—such a shame Apple wouldn't maintain compatibility.)

New icon too, with a Catalina-inspired palette:

Download Replay Gain Scan Release 0.3