simplewallet: save fixes in RPC mode

^C when in RPC mode would not save the wallet while it was still
refreshing after starting up.

Also, save the wallet out of the signal handler. We don't want
to call complex stuff in a signal handler.

src/simplewallet/simplewallet.cpp

@@ -2963,12 +2963,25 @@ int main(int argc, char* argv[])
     }
 
     tools::wallet2 wal(testnet,restricted);
+    bool quit = false;
+    tools::signal_handler::install([&wal, &quit](int) {
+      quit = true;
+      wal.stop();
+    });
     try
     {
       LOG_PRINT_L0(sw::tr("Loading wallet..."));
       wal.load(wallet_file, password);
       wal.init(daemon_address);
       wal.refresh();
+      // if we ^C during potentially length load/refresh, there's no server loop yet
+      if (quit)
+      {
+        LOG_PRINT_L0(sw::tr("Storing wallet..."));
+        wal.store();
+        LOG_PRINT_GREEN(sw::tr("Stored ok"), LOG_LEVEL_0);
+        return 1;
+      }
       LOG_PRINT_GREEN(sw::tr("Loaded ok"), LOG_LEVEL_0);
     }
     catch (const std::exception& e)
@@ -2979,10 +2992,8 @@ int main(int argc, char* argv[])
     tools::wallet_rpc_server wrpc(wal);
     bool r = wrpc.init(vm);
     CHECK_AND_ASSERT_MES(r, 1, sw::tr("Failed to initialize wallet rpc server"));
-
     tools::signal_handler::install([&wrpc, &wal](int) {
       wrpc.send_stop_signal();
-      wal.store();
     });
     LOG_PRINT_L0(sw::tr("Starting wallet rpc server"));
     wrpc.run();