from  Benoît Perrot  <benoit@lrde.epita.fr>

	* src/vm/memory.hh, src/vm/mmu.hh, src/vm/virtual_machine.cc:
	Make the MMU responsible of address translation and exception 
	raising.
	* src/vm/cp0.hh (raise_addr_load, raise_addr_store): Add address
	load and store exception.
	* src/vm/virtual_machine.hh (execute): Stop execution on fatal
	exceptions.