Got fairly far along in my triage of my backlog, looking through everything
that happened after January 23rd. Still 39 or so items to look at.

There have been several reports of problems with ssh password prompts.
I'm beginning to think the assistant may need to prompt for the password
when setting up a ssh remote. This should be handled by `ssh-askpass` or
similar, but some Linux users probably don't have it installed, and there
seems to be no widely used OSX equivalent.

---

Fixed several bugs today, all involving (gasp) direct mode.

The tricky one involved renaming or deleting files in direct mode.
Currently nothing removes the old filename from the direct mode
mapping, and this could result in the renamed or deleted file
unexpectedly being put back into the tree when content is downloaded.

To deal with this, it now assumes that direct mode mappings may be out of
date compared to the tree, and does additional checks to catch
inconsistencies. While that works well enough for the assistant,
I'd also like to make the `pre-commit` hook update the mappings for files
that are changed. That's needed to handle things like `git mv`.
