Drag drop Codon alignment file, but it disappears

[walterxie]

Drag drop the file to panel. After select the genetic code, the file seems disappear.

AlignmentListInputEditor needs to improve:

table.setOnDragDropped((DragEvent event) -> {
           Dragboard db = event.getDragboard();
       	if (db.hasFiles()) {
       		addItem(db.getFiles().toArray(new File[] {}));
           } else {
               event.setDropCompleted(false);
           }
           event.consume();
       });
` ``

[walterxie]

A wired exception using drag-drop, but not happened if load from File menu.

Could not find beastObject with id treeLikelihood.codon. Typo in template perhaps?

Exception in thread "JavaFX Application Thread" java.lang.NullPointerException: Cannot read field "dataInput" because "likelihood" is null
	at beastfx.app.inputeditor.AlignmentListInputEditor.addItem(AlignmentListInputEditor.java:1195)
	at beastfx.app.inputeditor.AlignmentListInputEditor.lambda$init$0(AlignmentListInputEditor.java:162)
	at javafx.base/com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
	at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:234)
	at javafx.base/com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)