Bind playlist properties to pad view

.../de/tobias/playpad/layout/desktop/pad/DesktopPadView.java

.../playpad/layout/desktop/pad/DesktopPadViewController.java

...java/de/tobias/playpad/layout/touch/pad/TouchPadView.java

...bias/playpad/layout/touch/pad/TouchPadViewController.java

...main/java/de/tobias/playpad/pad/content/Playlistable.java

...tobias/playpad/pad/viewcontroller/IPadViewController.java

...ypad/plugin/content/pad/ContentPlayerMediaContainer.scala

.../playpad/plugin/content/pad/ContentPlayerPadContent.scala

.../playpad/plugin/content/pad/ContentPlayerPadPreview.scala