Finally got issue 777

I was wrong, the recursion was not due to weird call order of WGuiList and WGuiMenu at all. It was due to two different problems:
1) there is some code in WGuiMenu to handle keys previously held. I guess it's to be able to go through the options very quickly on PSP.
2) Each PSP generated keys stays held if the corresponding code for release is not called...

=> Each time we generate some PSP keys press from gesture in the core or in a frontend, we absolutely need to generate the release code corresponding or the core might think that some keys are still held ... That's precisely what was not done by the code handling swipe in filters =).

JGE/src/qt/corewrapper.cpp

@@ -133,6 +133,7 @@ void WagicCore::timerEvent( QTimerEvent* )
     m_engine->SetDelta((float)dt / 1000.0f);
     m_engine->Update((float)dt / 1000.0f);
 
+    done();
     update();
 }