Implement using media folder in pad content types

...ypad/layout/desktop/DesktopMenuToolbarViewController.java

...bias/playpad/layout/desktop/DesktopPadViewController.java

PlayWall/src/de/tobias/playpad/pad/content/AudioContent.java

...viewcontroller/option/project/PathsTabViewController.java

...de/tobias/playpad/viewcontroller/pad/PadDragListener.java

...llCore/src/de/tobias/playpad/pad/conntent/PadContent.java

...gin/de/tobias/playpad/mediaplugin/image/ImageContent.java

...gin/de/tobias/playpad/mediaplugin/video/VideoContent.java