Debugger: Fix Symbian.

...which subclasses DebuggerRunner and does not call
DebuggerPlugin::startDebugger(), which connects the
engine, leading to strange malfunctions. Move functionality
to DebuggerRunner::start() to make it self-contained.
Add object names to engines for easier debugging.

Reviewed-by: hjk

src/plugins/debugger/script/scriptengine.cpp

@@ -204,6 +204,7 @@ void ScriptAgent::scriptUnload(qint64 scriptId)
 ScriptEngine::ScriptEngine(const DebuggerStartParameters &startParameters)
     : DebuggerEngine(startParameters)
 {
+    setObjectName(QLatin1String("ScriptEngine"));
 }
 
 ScriptEngine::~ScriptEngine()