Merge branch 'jh/status-no-ahead-behind'

"git status" can spend a lot of cycles to compute the relation
between the current branch and its upstream, which can now be
disabled with "--no-ahead-behind" option.

* jh/status-no-ahead-behind:
  status: support --no-ahead-behind in long format
  status: update short status to respect --no-ahead-behind
  status: add --[no-]ahead-behind to status and commit for V2 format.
  stat_tracking_info: return +1 when branches not equal

wt-status.h

@@ -5,6 +5,7 @@
 #include "string-list.h"
 #include "color.h"
 #include "pathspec.h"
+#include "remote.h"
 
 struct worktree;
 
@@ -87,6 +88,7 @@ struct wt_status {
 	int show_branch;
 	int show_stash;
 	int hints;
+	enum ahead_behind_flags ahead_behind_flags;
 
 	enum wt_status_format status_format;
 	unsigned char sha1_commit[GIT_MAX_RAWSZ]; /* when not Initial */