Many commands learned to pay attention to submodule.recurse
configuration.

* sb/submodule-blanket-recursive:
  builtin/fetch.c: respect 'submodule.recurse' option
  builtin/push.c: respect 'submodule.recurse' option
  builtin/grep.c: respect 'submodule.recurse' option
  Introduce 'submodule.recurse' option for worktree manipulators
  submodule loading: separate code path for .gitmodules and config overlay
  reset/checkout/read-tree: unify config callback for submodule recursion
  submodule test invocation: only pass additional arguments
  submodule recursing: do not write a config variable twice