* bug when annexing files in a subdir of a git repo
* how to handle git mv file?

* query remotes for their annex.name settings, or figure out a different
  solution to nameing problem?

  - querying network remotes all the time will be slow. local caching in
    .git/config?
  - having a git annex name and a git remote name that are distinct
    will be confusing
  - but git remote names are repo-local, I want a global name
  - really, I don't want a name at all, I want a per-repo UUID

  So, each repo has a UUID, stored in annex.uuid.
  
  And also, the last seen UUID for each remote is listed:

  remote.origin.annex-uuid=d3d2474c-d5c3-11df-80a9-002170d25c55

  Then when it need to find a repo by UUID, it can see if a known remote
  has it -- and then query the remote to confirm the repo there still has
  that UUID (a different repo may have been mounted there).

  Failing that, it can force a refresh of all uuids, updating .git/config,
  and check again.

  - Only downside for this is that if I put a repo on a usb disk,
    and it is disconnected and I have no remote for it,
    git-annex will have to say:

    "You asked for a file that is only present on a git repo with
     UUID d3d2474c-d5c3-11df-80a9-002170d25c55 -- and I don't know
     where it is."

   To solve that, let .git-annex/uuid.map map between uuids and descriptions,
   like "d3d2474c-d5c3-11df-80a9-002170d25c55 SATA drive labeled '* arch-2'"

* hook up LocationLog
* --push/--pull/--get/--want/--drop

* finish BackendUrl and BackendChecksum