ErrorStatus of AudioFiles not checked after creation

[weefuzzy]

IAudioFile does all its parsing in the constructor, and sets an error flag if a problem is encountered. We're not checking that flag, which means worse things can happen further down the line if a file has not been read successfully.

See this forum post: https://discourse.flucoma.org/t/using-extended-wav-format-throws-floating-point-exception-for-cli-reacoma-versions/663

The root problem here is that IAudioFile barfs on the Wave Extensible FMT chunk, but doesn't give as a good an error as it could (instead of 'unsupported format', one gets a mysterious floating point exception). [I shall see about getting support for the wav extensible header added to the HISSTools audio file library]