[PATCH evolve] prune: update to successor rather than parent whenkilling '.''

[Sean Farley]

dan at cabo.dk writes:

> # HG changeset patch
> # User Dan Villiom Podlaski Christiansen <dan at cabo.dk>
> # Date 1389263595 -3600
> #      Thu Jan 09 11:33:15 2014 +0100
> # Node ID 5d03689228e8b7006f22d2c6da219f9136a64421
> # Parent  d5e25eaaee317a4bcf238b3adba7526d807dd0cc
> prune: update to successor rather than parent when killing '.'

I'm unsure about this change. At the very least, it should have a flag
to turn it off. There are operations I do where I prune a lot of
contiguous changesets in a for loop where doing an update would
dramatically increase the time.

I'm open to changing my ways, though, if prune could take a range for
both the -r and -s arguments.