[PATCH 1 of 4 V3 part 2] revlog: move ancestor generation out to a new class

[Siddharth Agarwal]

On 12/18/2012 02:30 AM, Pierre-Yves David wrote:
> I think we should honor stoprev here. That seems more sensible.

I would be far more comfortable doing this in a separate patch series.

I've addressed the rest of your comments; thanks.