s/drag'n'drop/drag and drop/
Main/GuestDnD: warings
DnD: Autocallers, locking.
DnD: Added support for dynamically managing formats on the host.
DnD: Solaris build fix; no C++11 features available (yet).
DnD: API overhaul; now using IDnDTarget + IDnDSource. Renamed DragAndDrop* enumerations to DnD*. Also rewrote some internal code.