DnD: Implemented guest->host drag'n drop for X11-based guests.
DnD/HostService: Defer client calls if drag'n drop mode is set to disabled.
DnD: Bugfixes for Linux hosts.
DnD: Update, bugfixes.
DnD: Update.
DnD: build fix and warnings
DnD/HostServices: A bit of cleanup.
DnD: First working implementation for Windows guest->host support; still work in progress. As for now only pure text data can be dragged over.
Merged private draganddrop branch into trunk.
HostServices/DragAndDrop: play safe when removing clients from the queue
dnd: debug leftover
enabled shared clipboard support for Linux hosts (guest=>host only)