current linux vm build is broken.

the platform display plugin now expects a ioScreenScaleFactor

function that isn't defined for vm-display-X11 and vm-display-null

and some defines in sq.h had changed

from

DragLeave to SqDragLeave (and the same for all other drag events).

And maybe more, but fixing the above changes, I was at least able to

build a vm

nicolai