t / t5100 / rfc2047-info-0004on commit status: add --[no-]ahead-behind to status and commit for V2 format. (fd9b544)
   1Author: Nathaniel Borenstein (םולש ןב ילטפנ)
   2Email: nsb@thumper.bellcore.com
   3Subject: Test of new header generator
   4