Issue 13: QT GUI: Result list tab traversal should have visual feedback

The recoll main window and its result list are entirely usable without the mouse, using tab-traversal. Unfortunately there is no feedback given when walking the links inside the result list so that it is difficult to know which one will be activated if <CR > is hit.

Need to see if Qt would allow something to be done.

Solved by the WebKit reslist, which does give feedback when tabbing the links