AUv2 and AUv3 compatibility

[djb-2]

See also:

Loading an iOS Logic project on macOS

Hi, Logic projects can be shared between the iPad Logic and macOS Logic, provided that the AUv3 plugin on iOS uses the same plugin id as the AUv2 plugin on macOS. With JUCE plugins, this works only in one direction: using iOS Logic to load a project created on a mac works, but in the other direction, when loading the iOS project on macOS, the ‘JuceAU::RestoreState’ method returns without calling AudioProcessor::setStateInformation : This is because this line: ComponentResult err = MusicDe…