hector_pose_estimation: use x,y,z for roll,pitch,yaw respectively in euler message (geometry_msgs/Vector3Stamped)
hector_pose_estimation_core: fixed bug in MagneticModel::getStateJacobian()

Conflicts:

	hector_pose_estimation_core/src/measurements/magnetic.cpp
Merge branch 'multiple_decoupled_system_models'

Conflicts:
	hector_pose_estimation_core/src/measurements/magnetic.cpp
Merge branch 'multiple_decoupled_system_models'
hector_pose_estimation_core: fixed yaw update indices
hector_pose_estimation_core: added first draft of system model GroundVehicleModel (copied from MonstertruckModel)