Parsons UI changes and parson's problems in turtle chapter

Added lots of parson's problems to the turtle chapter.
Changed UI to make the drag easier by setting the min height and width.
 Moved feedback after buttons.
Have a function that runs after the document.ready functions that both sets the min-height css as well as forces the height on the already rendered draggable area.  This should make the parson's problems more user friendly for drag and drop.