Merge branch 'mk/clone-recurse-submodules'

After "git clone --recurse-submodules", all submodules are cloned
but they are not by default recursed into by other commands.  With
submodule.stickyRecursiveClone configuration set, submodule.recurse
configuration is set to true in a repository created by "clone"
with "--recurse-submodules" option.

* mk/clone-recurse-submodules:
  clone: set submodule.recurse=true if submodule.stickyRecursiveClone enabled