fixed inertia parameters. added imu plugin--not working
changed some physical and collision properties.
Merge pull request #8 from jackal/spourmehr_jackal_sim

Updated URDF with new physical properties.
Add fork of diff_drive_controller.
Changes
0.2.0
Remove changelog entries which were confusing dpkg.
Depend on diff_drive_controller.
0.2.1
Add front laser accessory to description.
Merge pull request #9 from jackal/front-laser

Add front laser accessory to description.
Add comment about accessory args.
0.3.0
Add dep for joint state controller.
hector gazebo plugin for imu sensor is added
enabled gravity for laser