Merge branch 'jx/branch-vv-always-compare-with-upstream'

"git branch -v -v" (and "git status") did not distinguish among a branch that does not build on any other branch, a branch that is in sync with the branch it builds on, and a branch that is configured to build on some other branch that no longer exists. * jx/branch-vv-always-compare-with-upstream: status: always show tracking branch even no change branch: report invalid tracking branch as gone