Theming of description for filefieldmp3player could be more useful

The theme function/template description below the mp3player could be more useful. As it stands it only will handle a number of pieces of information; artist/album/title etc. This works for basic use cases. Consider sending in the entire getid3() info to make it maximally themeable and configurable.

My use case that spawned this request was to show the filesize and audio length as part of the description.