idea: blame-deps (aka 3D-blame)

The idea is to do something like

```
git deps some-file.txt
```

This will open the git-deps browser with the contents of the file loaded into a pane in a typical blame view:

```
e5392d87 1) This is some file.
e5392d87 2) =====================================
e5392d87 3)
69d951f2 4) Look at all the nice contents.
e5392d87 5)
```

The magical thing is that each of the revisions are clickable - doing so will open the git-deps graph for the clicked commit.

Begin at the `git deps some-file.txt` command entry point and the git-deps browser entry point; inspect how the blame view and commit graph are opened. Done means the file contents appear in a blame-style pane, each revision is clickable, and clicking one opens the graph for that commit.

Written by the indexing model from the issue text.