Add Opus paths & test

Remove noisy output

Prevent Ogg reader from silently returning broken reader when faced with non-Ogg data

Date

Header fixes

Tidy

Use doubles for rates

This turns out annoyingly not to be true - will need separate Opus on Win after all

Typo fix

Add Opus reader

Read artist/title metadata from file in CoreAudio reader

Avoid ringbuffer printing a warning

Provide alternate preprocessor flag for sndfile (because SV uses it), + fix typo

Fix some compiler warnings

Tidy

Further work on metadata

MediaFoundation fixes; fixes to metadata handling; rename Exceptions.cpp to something more distinct

Track and artist name

Fix some warnings

Compile fixes