RoPod/Tutorials/Copying External Repositories

If a non-standard ros-package should be added while maintaining the commits of the previous package, use the following commands (in this case, the ed_tutorials package is moved):

git remote add ed_tutorials_remote https://github.com/tue-robotics/ed_tutorials
git fetch ed_tutorials_remote
git merge -s ours --no-commit ed_tutorials_remote/master

git read-tree --prefix=ed_tutorials/ -u ed_tutorials_remote/master
git commit -m "Imported ed_tutorials as a subtree."
git mv ~/ropod-project/ed/ ~/ropod-project/catkin_workspace/src/functionalities/ED/