some initial support for local bare repos

This relies on git-annex's behavior of reading the config of local repos.
That allows repoIsLocalBare to examine the git config for core.bare.

Hopefully, gitAnnexLocation, gitAnnexDir, and gitAnnexObjectDir
are only used on local repos. But, I have not audited fully, since
they're probably not (see for example copyToRemote). And so,
the functions fall back to their old non-bare-aware behavior for
non-local repos.

Content.hs

@@ -51,8 +51,8 @@ calcGitLink file key = do
 	let absfile = case absNormPath cwd file of
 		Just f -> f
 		Nothing -> error $ "unable to normalize " ++ filePathToString file
-	return $ relPathDirToDir (parentDir absfile) (Git.workTree g) ++
-		annexLocation key
+	return $ relPathDirToDir (parentDir absfile) 
+			(Git.workTree g) </> ".git" </> annexLocation key
 
 {- Updates the LocationLog when a key's presence changes. -}
 logStatus :: Key -> LogStatus -> Annex ()