* vc.el (vc-status-headers): Rename from

* vc.el (vc-status-headers): Rename from
vc-status-insert-headers.  Just return header.
(vc-status-move-to-goal-column): New function.
(vc-status-mode-map): Define more keys.
(vc-status-mode): Use vc-status-refresh.  Now 'special.
(vc-status-refresh): New function.
(vc-status-next-line): Likewise.
(vc-status-previous-line): Likewise.
(vc-status-mark-file): Use vc-status-next-line.
(vc-status-unmark-file): Use vc-status-previous-line.
(vc-status-unmark-file-up): New function.
(vc-status-register): Likewise.
(vc-status-find-file): Likewise.
(vc-status-find-file-other-window): Likewise.
(vc-status-current-file): Likewise.
(vc-ensure-vc-buffer): Understand vc-status mode.