Support SDL_EVENT_DROP_TEXT in Windows
src/video/windows/SDL_windowsvideo.c + .h
Connect to COM WIN_CoInitialize + OLE OleInitialize in WIN_VideoInit
Disconnect from COM WIN_CoUninitialize + OLE OleUninitialize in WIN_VideoQuit
src/video/windows/SDL_windowswindow.c + .h
Create / Destroy IDropTarget or use fallback WM_DROPFILES
depending on OleInitialize success in WIN_VideoInit
Handle text/uri-list, text/plain;charset=utf-8, CF_UNICODE_TEXT, CF_TEXT, CF_HDROP
Call terminating WIN_AcceptDragAndDrop from WIN_DestroyWindow ( CleanupVideoData )