[emms-help] emms-mode-line-string for the first track incomplete

[William Xu]

I find that when i start to play a new playlist, the
emms-mode-line-string for the first track only shows its filename, even
if it has artist info. And seems it's caused by

    (later-do 'emms-info-really-initialize-track track)

from `emms-info-initialize-track'. Emms sets the incomplete
emms-mode-line-string before the first track's full info got
initialized. Based on this, one can run (emms-mode-line-alter-mode-line)
after a later-do-interval time to force an update. I haven't figured out
a clean way to accomplish this yet. What do you think?

ps. I sent a patch to show only short file name sans its directory on
mode line. 

--
William