Added separate odometry launch

launch/odometry.launch

+<!-- -->
+<launch>
+  <arg name="x"     default="0.0"/>
+  <arg name="y"     default="-0.2"/>
+  <arg name="yaw"   default="0.0"/>
+
+
+  <node pkg ="odometry"
+        type="odometry_publisher"
+        name="odometry_publisher"
+        output="screen">
+    <param name="file_name" value="/opt/ros/modelcar/catkin_ws/install/share/odometry/cfg/SteerAngleActuator.xml"/>
+    <param name="initial_x" value="$(arg x)"/>
+    <param name="initial_y" value="$(arg y)"/>
+    <param name="initial_yaw" value="$(arg yaw)"/>
+    <remap from="/manual_control/steering"
+             to="/steering_angle"/>
+    <remap from="/model_car/twist"
+             to="/twist"/>
+    <remap from="/model_car/yaw"
+             to="/yaw"/>
+    <remap from="~odom"
+             to="/odom"/>
+  </node>
+
+</launch>