"git format-patch" learned "--from[=whom]" option, which sets the
"From: " header to the specified person (or the person who runs the
command, if "=whom" part is missing) and move the original author
information to an in-body From: header as necessary.
* jk/format-patch-from:
teach format-patch to place other authors into in-body "From"
pretty.c: drop const-ness from pretty_print_context