update a few scripts

scripts/block_headers

@@ -0,0 +1,20 @@
+#!/usr/bin/env python
+
+# A simple script that connects to a server and displays block headers
+
+import time, electrum
+
+# 1. start the interface and wait for connection
+interface = electrum.Interface('electrum.no-ip.org:50002:s')
+interface.start(wait = True)
+if not interface.is_connected:
+    print "not connected"
+    exit()
+
+# 2. send the subscription
+callback = lambda _,result: electrum.print_json(result.get('result'))
+interface.send([('blockchain.headers.subscribe',[])], callback)
+
+# 3. wait for results
+while True:
+    time.sleep(1)