roscore-default: Removing not supported variable in variable
roscore-default: Adding PATH, LD_LIBRARY_PATH and PYTHONPATH
roscore.service: Using /opt/ros/hydro/bin instead of /usr/bin to launch
roscore

You can now install roslaunch-systemd :

opkg install roslaunch-systemd

and start roscore :

systemctl start roscore

This commit further adds a simple fix to the patch for the ros-comm
repository.