Pull in an other GIT repo into your own for modification.

For my led clock I wanted to be sure that I have the modified environment at all times.
After some googling I found this:

<pre>git remote add rack_remote
git fetch rack_remote
git merge -s ours --no-commit rack_remote/master
git read-tree --prefix=rack/ -u rack_remote/master
git commit -m "Imported rack as a subtree."</pre> 

Note that submodules will be gone.
I've fixed this by moving the .gitmodules file into my main repo and changed the paths