As presented here, the menu won't appear in the proper buffers, the
problem being that there's no "monotone-mode" being entered and hence
no way to decide when a given buffer should present the
monotone-specific menu. I've seen both the CVS and ClearCase
integration packages figure this out by defining a hook in
find-file-hooks that determines whether the current buffer is looking
at something within a repository. It makes opening such buffers
slightly slower, as there's usually a call to an external program, or
maybe just a search up the directory tree.