Playing audio should be stopped when all songs or the song now playing are removed.
Playing audio should be stopped when all songs or the song now playing are removed.

Change-Id: Ic667d49814d3f33bd3eb7b30efd64bf8cf4ed624
Issue-Id: #15
Reviewed-on: http://cr.qtquick.me/230
Tested-by: http://ci.qtquick.me/
Reviewed-by: Tasuku Suzuki <42980d970444f9101663582e70cd53623b3238b4@gmail.com>
Reviewed-by: Takahiro Hashimoto <b59128e2582a625f3a4337ede555b631692b1b94@qtquick.me>
Tested-by: Takahiro Hashimoto <b59128e2582a625f3a4337ede555b631692b1b94@qtquick.me>

qt-users-jp/qumoplayer,qt-users-jp/qumoplayer,qt-users-jp/qumoplayer