WPF - Improve DragDrop implementation
WPF - Improve DragDrop implementation

Improved for when drag/drop both originate and end within the browser. Reuse the CEF IDragData for DragTargetDragEnter call

No improvement has been made to dragging external items

Livit/CefSharp,Livit/CefSharp,Livit/CefSharp,Livit/CefSharp