Autosave Bugs

* Provided missing 'editor' argument to Autosave.request() call in autosave.js.coffee.
* Added user parameter to 'delete' ajax request so each user is only capable of deleting their own files
  * Added parameter to delete action in edit_controller
  * Added parameter to delete in autosave model and search for file based on first line and user id
* Modified delete in autosave model so it only deletes the file if it exists, this was returning internal server errors with successive clicks to the delete button.
* Added else case to the confirm dialog so when a user clicks cancel it deletes the existing autosave file.
* Cleaned up the Autosave test suite and tried to make things more explicit
* Commented out a line in autosave.js.coffee that set an interval to call the save method every 10 seconds. It seemed superfluous since autosave is being called a second after any edit is made to the file.