add Digital Bitbox hardware wallet

plugins/digitalbitbox/cmdline.py

@@ -0,0 +1,17 @@
+from digitalbitbox import DigitalBitboxPlugin
+from electrum.util import print_msg
+
+class DigitalBitboxCmdLineHandler:
+    def stop(self):
+        pass
+
+    def show_message(self, msg):
+        print_msg(msg)
+
+    def get_passphrase(self, msg, confirm):
+        import getpass
+        print_msg(msg)
+        return getpass.getpass('')
+
+class Plugin(DigitalBitboxPlugin):
+    handler = DigitalBitboxCmdLineHandler()