gitk highlight feature

I just pushed out some changes to gitk which allow you to use one view to highlight another (see the "Highlight" submenu under the "View" menu), and which allow you to specify arbitrary git-rev-list arguments for a view. The arguments string uses shell quoting conventions.

I had been thinking of having fields in the view editor dialog where you could put in refs that you did and didn't want included, date specifiers, etc., all in separate fields with suitable labels. Now I'm thinking that it's probably just as convenient to put "ORIG_HEAD.." into the git-rev-list arguments field as it is to put "ORIG_HEAD" in the "Don't include commits reachable from this" field. There may be an argument for having fields for "Exclude commits before this date" and "Exclude commits after this date", because those things often have spaces in them (e.g. "2 weeks ago") which would have to be quoted in the git-rev-list arguments field.

Thoughts?

Paul.