This modifies pretty_print_commit() to make the output of git-rev-list and
friends a bit more predictable.
A commit body starting with blank lines might be unheard-of, but still possible
to create using git-commit-tree (so is bound to appear somewhere, sometime).
Signed-off-by: Lars Hjemli <hjemli@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>