Debugger: add a new bool setting to follow all branches after fork

Currently unused.

Change-Id: Ic751de17bf43749a135b353c0b916371174b35f8
Reviewed-by: hjk <qthjk@ovi.com>

src/plugins/debugger/gdb/gdbengine.cpp

@@ -4841,6 +4841,11 @@ void GdbEngine::startGdb(const QStringList &args)
 
     // Dummy command to guarantee a roundtrip before the adapter proceed.
     postCommand("pwd", ConsoleCommand, CB(reportEngineSetupOk));
+
+    if (debuggerCore()->boolSetting(MultiInferior)) {
+        //postCommand("set follow-exec-mode new");
+        postCommand("set detach-on-fork off");
+    }
 }
 
 void GdbEngine::reportEngineSetupOk(const GdbResponse &response)