Merge branch 'dvfs'

Added DVFS and energy consumption support.

diff --cc include/msg/msg.h
Simple merge

diff --cc include/simgrid/simix.h
Simple merge

diff --cc src/msg/msg_host.c
Simple merge

diff --cc src/simix/smx_host.c
Simple merge

diff --cc src/simix/smx_host_private.h
Simple merge

diff --cc src/simix/smx_smurf_private.h
Simple merge

diff --cc src/simix/smx_user.c
Simple merge