Merge branch 'jk/startup-info' into maint

The startup_info data, which records if we are working inside a repository (among other things), are now uniformly available to Git subcommand implementations, and Git avoids attempting to touch references when we are not in a repository. * jk/startup-info: use setup_git_directory() in test-* programs grep: turn off gitlink detection for --no-index mailmap: do not resolve blobs in a non-repository remote: don't resolve HEAD in non-repository setup: set startup_info->have_repository more reliably setup: make startup_info available everywhere