processor_odom_2d exact integration if theta != 0

processor_odom_2d has two integration functions :

• exact integration if theta != 0 (impl : theta > 10e-3)
• Runge-Kutta integration otherwise

Added a test with data :

test_processor_odom_2d ~/path/to/wolf/src/example/data/odom_2d_loop.dat .

Data are basically ROS geometry_msgs/TwistStamped recorded from TIAGo. The robot in moving around for 90sec coming back to its starting point with but facing back ( ~ x:0 y:0 theta:pi ).

See e.g. slide 5