Add a public method to the appropriate class (AudioFile ?) to get the start-byte of the audio

[IJabz]

From https://java.net/jira/browse/JAUDIOTAGGER-393

Could you please add a public method to the appropriate class (AudioFile ?) to get the start-byte of the audio.

Reason why I request this is I would like to create an MD5-hash of audiofiles, but only of the parts of the file that rarely change with normal user experience. The idea is to create rudimentary duplication finding (beside the obvious tag duplicate, which isn't always enough).

[IJabz]

I assume we need end of actual audio as well ?

[IJabz]

Done, added getAudioStartPos() and getAudioEndPos() methods to AudioHeader interface and implemented for most formats