Merge branch 'yn/git-jump-emacs'

"git jump" (in contrib/) learned to present the "quickfix list" to its standard output (instead of letting it consumed by the editor it invokes), and learned to also drive emacs/emacsclient. * yn/git-jump-emacs: git-jump: invoke emacs/emacsclient git-jump: move valid-mode check earlier git-jump: add an optional argument '--stdout'