Make *git-messenger* buffer reuses magit-commit-mode if available

[tuhdo]

I think magit-commit-mode is really suitable for *git-messenger* buffer to show git output from d, s and S commands. It has highlighting and able to press q to quit.

[syohex]

I'll add hook for such purpose.

[syohex]

Please try to add following configuration.

(add-hook 'git-messenger:popup-buffer-hook 'magit-commit-mode)

[tuhdo]

Thanks. Please add to the homepage in the sample configuration section.

[syohex]

Done