Prototype git commit viewer

Over the weekend I hacked up a prototype viewer for git commits in Tk. It's called gitk and is at:

	http://ozlabs.org/~paulus/gitk

(that's the actual script itself :).

It displays a window with two panes; the upper one shows a summary of all the commits with a graph on the left showing the relationship of the commits (each dot represents a commit, with lines joining parents and children). The list is displayed with the most recent commit at the top, and parents below their children.

If you click on a commit, the bottom pane shows more details of the commit including the commit comments.

I plan to add a pane to show the list of files changed by the commit, and provide a way to pop up a dirdiff-style diff viewer window to view the actual diffs. I also plan to add a way to view the diffs between arbitrary points in the graph using girdiff. There is quite a lot of UI tweaking to be done too. However, it's already quite useful in its current state.

Paul.