Add --pretty=fuller

git log without --pretty showed author and author-date, while
with --pretty=full showed author and committer but no dates.
The new formatting option, --pretty=fuller, shows both name and
timestamp for author and committer.

Signed-off-by: Junio C Hamano <junkio@cox.net>

commit.h

@@ -43,6 +43,7 @@ enum cmit_fmt {
 	CMIT_FMT_DEFAULT = CMIT_FMT_MEDIUM,
 	CMIT_FMT_SHORT,
 	CMIT_FMT_FULL,
+	CMIT_FMT_FULLER,
 	CMIT_FMT_ONELINE,
 };