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/pdb/pdbengine.cpp

@@ -87,7 +87,9 @@ namespace Internal {
 
 PdbEngine::PdbEngine(const DebuggerStartParameters &startParameters)
     : DebuggerEngine(startParameters)
-{}
+{
+    setObjectName(QLatin1String("PdbEngine"));
+}
 
 PdbEngine::~PdbEngine()
 {}