Comment 1 for bug 351919

Maybe just show an abbreviated form of the following eg. c1wt4b7r6 when we have a unnamed format. This can be a little ugly but still informative.
       control: Meta directory format 1
  working tree: Working tree format 4
        branch: Branch format 7
    repository: Packs 6 (uses btree indexes, requires bzr 1.9)