Various fixes for command line. Make 'payto' command require network (fixes #1525)

scripts/get_history

@@ -1,7 +1,8 @@
 #!/usr/bin/env python
 
 import sys
-from electrum import Network, print_json
+from electrum import Network
+from electrum.util import json_encode, print_msg
 
 try:
     addr = sys.argv[1]
@@ -12,4 +13,4 @@ except Exception:
 n = Network()
 n.start()
 h = n.synchronous_get(('blockchain.address.get_history',[addr]))
-print_json(h)
+print_msg(json_encode(h))