MINOR: log: add '%Tl' to log-format

The '%Tl' is similar to '%T', but using local timezone.
diff --git a/include/common/standard.h b/include/common/standard.h
index ff87cd1..4813065 100644
--- a/include/common/standard.h
+++ b/include/common/standard.h
@@ -676,6 +676,9 @@
 
 extern const char *monthname[];
 
+/* numeric timezone (that is, the hour and minute offset from UTC) */
+char localtimezone[6];
+
 /* date2str_log: write a date in the format :
  * 	sprintf(str, "%02d/%s/%04d:%02d:%02d:%02d.%03d",
  *		tm.tm_mday, monthname[tm.tm_mon], tm.tm_year+1900,
@@ -693,6 +696,13 @@
  */
 char *gmt2str_log(char *dst, struct tm *tm, size_t size);
 
+/* localdate2str_log: write a date in the format :
+ * "%02d/%s/%04d:%02d:%02d:%02d +0000(local timezone)" without using snprintf
+ * return a pointer to the last char written (\0) or
+ * NULL if there isn't enough space.
+ */
+char *localdate2str_log(char *dst, struct tm *tm, size_t size);
+
 /* Dynamically allocates a string of the proper length to hold the formatted
  * output. NULL is returned on error. The caller is responsible for freeing the
  * memory area using free(). The resulting string is returned in <out> if the
diff --git a/include/types/log.h b/include/types/log.h
index 8c28310..ce0c717 100644
--- a/include/types/log.h
+++ b/include/types/log.h
@@ -57,6 +57,7 @@
 	LOG_FMT_PID,
 	LOG_FMT_DATE,
 	LOG_FMT_DATEGMT,
+	LOG_FMT_DATELOCAL,
 	LOG_FMT_TS,
 	LOG_FMT_MS,
 	LOG_FMT_FRONTEND,