Model of Mozilla host objects.

@author Magnus Madsen <magnusm@cs.au.dk> @author Matthias Diehn Ingesman <mdi@cs.au.dk> @author Anders Møller <amoeller@cs.au.dk> @author Peter Thiemann <thiemann@informatik.uni-freiburg.de> @author Simon Holm Jensen <simonhj@cs.au.dk>