Fixed up and begun implementing playlist
Were some problems with the change of directory structure--should mpvhandler be in the widget's directory? Should mpvhandler be a widget? The playlist already loads files from the command-line, how it will function has yet to be established. The old baka mplayer would see the files in the current directory but perhaps we want to take the same approach mpv has taken with playlist and maybe even perhaps use mpv's playlist functionality.  In other notes--this directory modification has some implications to compilation, I'll decide in the near future if it is worth the trouble or if we should have a flat directory structure.