* Adds configuration options for ReplayGain as well as adds them to the configuration dialog box.
* Adds the volume to the info box (I'm thinking maybe this should later say "computed volume" and be preceded by a list of the tags associated to the file).
* Sadly, Winamp requires the methods related to opening, closing, seeking and getting data to basically be duplicated for the extended read functionality to work...
* ReplayGain is intentionally ignored in the extended read functionality so that Winamp ReplayGain calculator can function properly.
* NOTE: I think maybe the extended read functionality should ignore looping forever?
