qtscript: Rename label() to getObject(), keeping an alias in place for label()
for compatibility. Also adding getObject(x, y) for getting a structure or
feature at given position, and getObject(type, player, id) for getting an object
by its unique ID. This latter form deprecates hackGetObj(). Adds some documentation
for the GROUP label type. Finally makes super cyborgs get DROID_CYBORG droid type
instead of DROID_WEAPON.