Whew, I got the finishing touches on the import tree feature, and it's
merged into master! Still work to do on that, particularly supporting more
interesting special remotes than directory. It may be two or three weeks
until I get back to working on it.

Even with only directory special remotes, some nice things can be done with
this. Like bi-directional syncing between a removable drive with no
git-annex repository on it, and a subdirectory of the git-annex repository:

	$ git config remote.drive.annex-tracking-branch master:subdir
	$ date > /mnt/new-from-drive
	$ date > subdir/new-from-repo
	$ git annex add
	add subdir/new-from-repo ok
	$ git annex sync --content
	commit
	 1 file changed, 1 insertion(+)
	 create mode 120000 subdir/new-from-repo
	ok
	list drive ok
	import drive new-from-drive ok
	update refs/remotes/drive/master ok
	
	Merge made by the 'recursive' strategy.
	 subdir/new-from-drive | 1 +
	 1 file changed, 1 insertion(+)
	 create mode 120000 subdir/new-from-drive
	export drive new-from-repo ok
