Merge branch 'jk/run-command-use-shell'

* jk/run-command-use-shell: t4030, t4031: work around bogus MSYS bash path conversion diff: run external diff helper with shell textconv: use shell to run helper editor: use run_command's shell feature run-command: optimize out useless shell calls run-command: convert simple callsites to use_shell t0021: use $SHELL_PATH for the filter script run-command: add "use shell" option