Close #5583

Playlist is cached/updated locally within browser instead of
refreshing after each function call.
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

(cherry picked from commit 60758c0313ef5553515bbc545dc5aa4b9299ca3c)
(cherry picked from commit b4cf7a9b5b5c568dd2cec85ff880f92703999814)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>