Have network_proxy use ThreadJob framework

Rename WalletSynchronizer to Synchronizer so that diagnostic messages,
which are based on class name, still refer to Synchronizer.

lib/network_proxy.py

@@ -60,15 +60,13 @@ class NetworkProxy(util.DaemonThread):
         self.blockchain_height = 0
         self.server_height = 0
         self.interfaces = []
-        self.jobs = []
         # value returned by estimatefee
         self.fee = None
 
 
     def run(self):
         while self.is_running():
-            for job in self.jobs:
-                job()
+            self.run_jobs()    # Synchronizer, for now
             try:
                 response = self.pipe.get()
             except util.timeout: