Browser Side: Widgets can now be moved, header (title bar) is draggable: - DragLabel moved to tools - new LiberviaDragWidget which manage currently dragged widget - getLiberviaWidgetsCount give number of widget of WidgetsPanel - LiberviaWidget's header has now its own class - new "WIDGET" drag type /!\ not fully finished, can crash if moved on the bad border (like last row border if the widget is the only one on this row)