Added several launch files for simulation:

 * sim_od_gp_ack_lp: launch the navigation with the opendrive global planner and the ackerman local planner without map.
 * launch/sim_od_gp_ack_lp_odom_ekf: launch the navigation with the opendrive global planner and the ackerman local planner without map, using the robot_localization node to estimate the odom frame.
 * sim_od_gp_ack_lp_all_ekf: launch the navigation with the opendrive global planner and the ackerman local planner without map, using the robot_localization node to estimate the odom frame and using the AMCL for global localization.
 * sim_sbpl_gp_ack_lp: launch the navigation with the SBPL global planner and the ackerman local planner without map.
 * launch/sim_sbpl_gp_ack_lp_odom_ekf: launch the navigation with the SBPL global planner and the ackerman local planner without map. using the robot_localization node to estimate the odom frame.
 * sim_mapping: launches the gmapping node to create a map. Using the opendrive global_planner and the ackermann local planner.