[Lazarus] Decision required WRT dragging

[Hans-Peter Diettrich]

Currently dragging is broken in the LCL, see Mantis #18525. Currently 
any attempt to undock a docked window makes at least a Windows 
application hang, in an unusable state, until a *different* application 
is activated by the user.

I see no reason why the submitted patch should not be applied, in order 
to make the DragManager more robust. The patch only affects dragging 
operations, has no effect when nothing is being dragged.

The arguments, why the patch should *not* be applied, deserve an 
substancial proof. Can anybody provide an example, where the fixed 
DragManager code would cause any *real* problems?

DoDi