Merge branch 'jl/submodule-diff-dirtiness'

* jl/submodule-diff-dirtiness: git status: ignoring untracked files must apply to submodules too git status: Fix false positive "new commits" output for dirty submodules Refactor dirty submodule detection in diff-lib.c git status: Show detailed dirty status of submodules in long format git diff --submodule: Show detailed dirty status of submodules