Add background Audio Feature

Merge pull request #15 from rAbdelHadi/patch-2

fix feature Background Audio

HotFix

Address:

1. SoundCloud Thumbnail is Low Quality
2. SoundCloud Plugin Slide Is Blue

HotFix

SOUNDCLOUD: Blank space should not show if there is nothing in the wysiwyg

Release

1. Release notes known issues(Sound Cloud):

• Multiple notifications of a successful removal of a track in playlist is shown if the user removes a song from the playlist
• Play button doesn't change to Pause button if the song in the playlist is being played in the track's profile
• Playback is paused on device lock
• No notification/popup on clicking on Add from the playlist button in the media player
• Widget player doesn't work (Can't play/skip/back) when device is locked
• Lock screen widget shows https://api.soundclound.com url to currently played track
• Player doesn't pause playback after application was minimized
• Set Volume method is not defined in audioPlayer.js (Volume not working)