[PATCH 0/7] git-submodule enhancements

This patch series do following enhancements for git-submodule

  - Fall back on .gitmodules if info not found in $GIT_DIR/config
  - multi-level module definition
  - Don't die when command fails for one submodule 

with diffstat

 git-submodule.sh           |  316 +++++++++++++++++++++++++++++++-------------
 t/t7400-submodule-basic.sh |   31 ++++-

and commits

      git-submodule: Avoid 'fatal: cannot describe' message
      git-submodule: Extract functions module_info and module_url
      git-submodule: Extract absolute_url & move absolute url logic to module_clone
      git-submodule: Fall back on .gitmodules if info not found in $GIT_DIR/config
      git-submodule: Extract module_add from cmd_add
      git-submodule: multi-level module definition
      git-submodule: Don't die when command fails for one submodule