Patch Set 3:

Here is what the `git help submodule` doc says:


 <repository> is the URL of the new submodule’s origin repository. This may be either an absolute URL, or (if it begins with ./ or ../), the location relative to the superproject’s origin
           repository (Please note that to specify a repository foo.git which is located right next to a superproject bar.git, you’ll have to use ../foo.git instead of ./foo.git - as one might expect
           when following the rules for relative URLs - because the evaluation of relative URLs in Git is identical to that of relative directories). If the superproject doesn’t have an origin
           configured the superproject is its own authoritative upstream and the current working directory is used instead.