gitk highlight feature

[Paul Mackerras <paulus@samba.org>]

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.