Creates [and removes] directory junction links from nested submodules to the top-most repository.
Start:
Repository
-> Submodules
-> Foo
-> Bar
-> Submodules
-> Foo
submodulelink Repository
Repository
-> Submodules
-> Foo
-> Bar
-> Submodules
-> Foo (junction link to Repository/Submodules/Foo)
submodulelink /u Repository
Repository
-> Submodules
-> Foo
-> Bar
-> Submodules
-> Foo (Empty dir)
Note: Submodule directories will not be modified if not empty.