## Adjust Comment for iTunes

In mp3 and aiff files, iTunes will only process comments with an empty description field and a language code of eng. If you are editing files previously edited by a different tagger it is possible that the default comment has a language code of xxx which may be used for don't care. This function will traverse the comments in a file and if no valid default comment is found it will look for comments with an empty description and a language code other than eng. If one is found, the function will change the language code to eng so that it is recognized by iTunes.