qmlplayer: list item translation
qml add video decoder options. workaround for variant map

QVariantMap is better to interact with js object.
QVariantHash is not supported in qml. So it's better to
change AVPlayer.setOptionsXXX argument to QVariantMap
qoptions: crash if command line value not given at the end
set invalid mediaStopPosition if duration is not valid

for example camera