fixed wrong time of MultiLevelLaserScans

Inside the simulator base::time::now is used for
setting the time of the scan. This is wrong, as
the simulation time differs from real time.
This had a great impact as the stream aggregator
started dropping samples in every tasks that was
processing the MLLSs.
Moved the getTime functionallity to Mars

Conflicts:

	tasks/Mars.cpp
	tasks/Mars.hpp
	tasks/MarsPlugin.cpp
	tasks/MarsPlugin.hpp
Merge branch 'rotating_ray_sensor_mlls' of https://github.com/shoppel/simulation-orogen-mars into rotating_ray_sensor_mlls
getTime moved to Mars
Merge pull request #3 from shoppel/rotating_ray_sensor_mlls

Rotating ray sensor mlls