Small fixs for the videos multi list.

Added two new methods:

• GetYT_VideoID: Returns the videoID from a youtube URL.
• PlayVideo: If the player is already initialized and we want to play another video, we should call this new function. It's only necessary the VideoId.

You can set the following advanced configuration options:

• setMuted: if true the video will start muted (default = false)
• setLoop: If true video will restart automatically when ended (default = false)
• showControls: if false video controls is hidden (default = true)
• showFullScreen: if false fullscreen icon is hidden (default = true)
  
  

If only width is set, height is automatically calculated using 16:9 ratio.