speed up relink script

[Brendan Cully]

On Friday, 23 March 2007 at 12:04, Brendan Cully wrote:
> It's better if collect skips .d files, and you don't do any reading at
> all (eg the md5) until after the prune phase. I doubt the md5 is
> needed - directly comparing the indexes is probably enough. I don't
> think the head-comparing stuff is about speed - it's about possibly
> relinking even more files.

I've fixed up hg-relink to only compare .d files now. I haven't done
the head-compare test yet, so it is maybe not relinking everything it
could. You're welcome to try other tricks to make it faster, like the
MD5 test.