- new function in WINGs: WMSetConnectionShutdownOnClose()

- new callback in the ConnectionDelegate structure: canResumeSending
- replaced setpgid() with setsid() when starting kids, to allow them to
  survive if wmaker (the parent) dies.
- a few cleanups.

src/main.c

@@ -307,8 +307,8 @@ ExecuteShellCommand(WScreen *scr, char *command)
 
 	SetupEnvironment(scr);
 
-#ifdef HAVE_SETPGID
-	setpgid(0, 0);
+#ifdef HAVE_SETSID
+        setsid();
 #endif
 	execl(shell, shell, "-c", command, NULL);
 	wsyserror("could not execute %s -c %s", shell, command);