Add config parameter to remove label popup

Close #271

labelme/app.py

@@ -987,7 +987,8 @@ class MainWindow(QtWidgets.QMainWindow, WindowMixin):
         text = None
         if items:
             text = items[0].text()
-        text = self.labelDialog.popUp(text)
+        if self._config['display_label_popup'] or not text:
+            text = self.labelDialog.popUp(text)
         if text is not None and not self.validateLabel(text):
             self.errorMessage('Invalid label',
                               "Invalid label '{}' with validation type '{}'"

labelme/config/default_config.yaml

@@ -1,4 +1,5 @@
 auto_save: false
+display_label_popup: true
 store_data: true
 keep_prev: false