Add signal handlers.

src/App.h

@@ -25,6 +25,9 @@
 #define __APP_H__
 
 
+#include <uv.h>
+
+
 class Network;
 class Options;
 
@@ -38,8 +41,16 @@ public:
   int exec();
 
 private:
+  void background();
+  void close();
+
+  static void onSignal(uv_signal_t *handle, int signum);
+
+  static App *m_self;
+
   Network *m_network;
   Options *m_options;
+  uv_signal_t m_signal;
 };