tests/test-diff-copy-depth.t

clone: allow local cloning to create more than one level of directories

I figure cloning a remote repository is more common, thus it's more likely that
some people might be relying on the less restrictive behavior.  Additionally,
`hg init` will also create more than one level of missing directories.

I also have a use case for reading the subrepos from .hgsub, and sharing them
into the normal nested location on the server.  SCM Manager doesn't host
subrepos in the normal nested location, which is nice for deduplicating the
repository data, but confuses `hg verify`.  Some of the subrepos are in the root
of the repositories, while others are one or two directories deep.  So not
having to build up the parent path first is desirable.

  $ for i in aaa zzz; do
  >     hg init t
  >     cd t
  > 
  >     echo
  >     echo "-- With $i"
  > 
  >     touch file
  >     hg add file
  >     hg ci -m "Add"
  > 
  >     hg cp file $i
  >     hg ci -m "a -> $i"
  > 
  >     hg cp $i other-file
  >     echo "different" >> $i
  >     hg ci -m "$i -> other-file"
  > 
  >     hg cp other-file somename
  > 
  >     echo "Status":
  >     hg st -C
  >     echo
  >     echo "Diff:"
  >     hg diff -g
  > 
  >     cd ..
  >     rm -rf t
  > done
  
  -- With aaa
  Status:
  A somename
    other-file
  
  Diff:
  diff --git a/other-file b/somename
  copy from other-file
  copy to somename
  
  -- With zzz
  Status:
  A somename
    other-file
  
  Diff:
  diff --git a/other-file b/somename
  copy from other-file
  copy to somename