Merge 'hv/submodule-config' to 'sb/submodule-helper'

* hv/submodule-config:
submodule: allow erroneous values for the fetchRecurseSubmodules option
submodule: use new config API for worktree configurations
submodule: extract functions for config set and lookup
submodule: implement a config API for lookup of .gitmodules values

diff --cc .gitignore
Simple merge

diff --cc Makefile
Simple merge

diff --cc builtin/checkout.c
index 9ff5ca4cbe97dd2dcd2cfa261d7f778809a88133,f1f168d2f60ab76a10641b57d9c0834f03a228a0..7ea533e4ab6a244297068fe8a376c094e7d42291
--- 1/builtin/checkout.c
--- 2/builtin/checkout.c
+++ b/builtin/checkout.c
@@@ -18,7 -18,10 +18,8 @@@
  #include "xdiff-interface.h"
  #include "ll-merge.h"
  #include "resolve-undo.h"
+ #include "submodule-config.h"
  #include "submodule.h"
 -#include "argv-array.h"
 -#include "sigchain.h"
  
  static const char * const checkout_usage[] = {
        N_("git checkout [<options>] <branch>"),

diff --cc builtin/fetch.c
Simple merge

diff --cc diff.c
Simple merge

diff --cc submodule.c
Simple merge