More robust shutdown sequence with warning on unclean shutdown.

src/frontend/stmclient.h

@@ -44,7 +44,9 @@ private:
   Network::Transport< Network::UserStream, Terminal::Complete > *network;
   Terminal::Display display;
 
+  std::wstring connecting_notification;
   bool repaint_requested, quit_sequence_started;
+  bool clean_shutdown;
 
   void main_init( void );
   bool process_network_input( void );
@@ -70,8 +72,10 @@ public:
       overlays(),
       network( NULL ),
       display( true ), /* use TERM environment var to initialize display */
+      connecting_notification(),
       repaint_requested( false ),
-      quit_sequence_started( false )
+      quit_sequence_started( false ),
+      clean_shutdown( false )
   {
     if ( predict_mode ) {
       if ( !strcmp( predict_mode, "always" ) ) {