Be able to move a QGraphicsItem (drag and drop)

[parkouss]

For now, funq is not able to select a QGraphicsItem and moves it. In fact the selesction does not works (by simulating mouse press on an item), and that's probably the problem here.

I'm doing some tests with the dnd-gitems branch. I'm sure the item receives a mouse press event, but still no luck... Let's investigate this more.