Merge branch 'jk/date-mode-format'

Teach "git log" and friends a new "--date=format:..." option to
format timestamps using system's strftime(3).

* jk/date-mode-format:
  strbuf: make strbuf_addftime more robust
  introduce "format" date-mode
  convert "enum date_mode" into a struct
  show-branch: use DATE_RELATIVE instead of magic number

log-tree.c

@@ -640,7 +640,7 @@ void show_log(struct rev_info *opt)
 			 */
 			show_reflog_message(opt->reflog_info,
 					    opt->commit_format == CMIT_FMT_ONELINE,
-					    opt->date_mode,
+					    &opt->date_mode,
 					    opt->date_mode_explicit);
 			if (opt->commit_format == CMIT_FMT_ONELINE)
 				return;