Added model to student vle, grading tool, and authoring tool.
Changed getProjectMetaData() to retrieveMetaData() because we use getProjectMetaData() now to get the project metadata from the model.
Made all steps call the pushStudentWork() function instead of firing the pushStudentWork event. The pushStudentWork() function then fires the studentWorkUpdated event that event handlers can listen for.
Made the view global and made nodes set their constraint status as well as fire an event that the NavigationPanel listens for.
more refactoring. moved navigation related functions to nav.js. removed old constraints
Changed all renderNode events to navigationNodeClicked or nodeLinkClicked events.
implemented branching based on student choice on MC step
implemented SVGDraw Node branching based on top score student received on auto grader.
updated translations
refactoring. removed unused functions and events. changed to call functions directly instead of calling them indirectly through event manager.
Merged model branch into master branch.