Play All option in All Music mode merely adds media to the playlist, it doesn't play them instantly
Steps to Reproduce:
1. Open All Music > Songs
2. Press Play All
Media are added to playlist, but not played
1. Playlist should be cleared, and media should start playing immediately
2. Put a separate option for "Add to Playlist"
This issue is fixed with commit tag http://quickgit.kde.org/?p=plasma-mediacenter.git&a=commit&h=8bbfd0f528f07f19821b2acdf2bdf0370a81a3c0 . Hence marking this bug as resolved and fixed.