Description:
- dragging tab or whole window will use half transparent "ghost" image of the window with real content. Ghost window
image will follow mouse cursor.
- ghost image should be rescaled to some maximized ghost image size, for performance and usability reasons
- ghost image should be created outside EQ thread, performance reasons
- image should visually move back to original location if drop was not succesfull
- image should darken a bit when dragged over area which is refusing drop - such indication will replace DnD cursors,
which are not that intuitive not reliable (problems on various platforms)

Dependencies, risks and fallbacks:
- JNA library allows access to ghost drag image. Without JNA, we will use non-transparent drag image. 
- Performance risk: We will need to change/improve/update winsys DnD architecture and glass pane usage to tune drag
performance.

Time estimation: 3 man weeks