Support both atlas v0 and v3

See https://github.com/start-jsk/rtmros_gazebo/issues/69.

Both atlas and atlas_v3 are available by following commands.
```
# for atlas_v3
roslaunch drcsim_gazebo atlas_sandia_hands.launch
rtmlaunch hrpsys_gazebo_atlas atlas_v0_hrpsys_bringup.launch
roscd hrpsys_gazebo_atlas/euslisp; roseus atlas-v0-interface.l "(atlas-init-ex)"

# for atlas_v0
roslaunch drcsim_gazebo atlas_v3_sandia_hands.launch
rtmlaunch hrpsys_gazebo_atlas atlas_v3_hrpsys_bringup.launch
roscd hrpsys_gazebo_atlas/euslisp; roseus atlas-v3-interface.l "(atlas-init-ex)"
```