[PATCH 12/18] update submodules: add submodule_move_head

In later patches we introduce the options and flag for commands that modify the working directory, e.g. git-checkout. This piece of code will be used universally for all these working tree modifications as it * supports dry run to answer the question: "Is it safe to change the submodule to this

[PATCH 12/18] update submodules: add submodule_move_head

In later patches we introduce the options and flag for commands that modify the working directory, e.g. git-checkout. This piece of code will be used universally for all these working tree modifications as it * supports dry run to answer the question: "Is it safe to change the submodule to this