how to checkout proper submodules

[Jan Stolarek]

For me the biggest plus of switching to submodules would be keeping GHC and testsuite in sync. If 
there are any reasons not to change in-tree library repos to submodules, then I would at least 
want testsuite to be changed to a submodule.

I also use github for my daily work on GHC and being able to send patches via Pull Requests would 
make things easier. On the other hand it might be more difficult to attach files to a ticket (no 
such feature on Github AFAIK).

Speaking of Github, perhaps we should put more stress on github folks to fix this: 
https://github.com/github/markup/issues/196 ?

Jan