Updated urdf creation script to define the middleware-specific environment variables after creating the bare coman.urdf file.
Fixed create_urdf_and_sdf to export middleware environment variables after setting them and before running the ros xacro script, and unsetting them after the xacro and gazebowtf scripts terminate.
Splitted sensor and foot masses, and moved sensor frame to actual pose of sensing element.
Check issue 11 for more details.
Put correct pose and inertial elements bias into .wtf file.
Check issue 11 for details.