Severity: wishlist Tags: patch  From a buffer visiting a file 
under version control one has the following two key bindings to 
display logs:

          C-x v l runs the command vc-print-log

          C-x v L runs the command vc-print-root-log

From a buffer in `vc-dir-mode' one has the key binding:

          l runs the command vc-print-log

But there is no `vc-print-root-log' key binding...