Fix gitmodules handling for clone command

[Kinokin]

• handle relative submodule url
• handle special branch '.'

[Reedbeta]

Thanks for the PR! I think the code can likely be simplified a lot using os.path.relpath and such rather than parsing the path yourself. See how I'm doing it for the submodule paths a few lines earlier:

git-partial-submodule/git-partial-submodule.py

Line 194 in bd8bb4e

submoduleRelPathsToProcess = [os.path.relpath(os.path.abspath(path), worktreeRoot)

Also, it looks like you used 3-space indents instead of 4 - I'd appreciate if you can clean that up. 🙂

[Kinokin]

Hi Nathan, yes, its a quick hack to get an experiment working. I can't spend any more time on this, sorry