[PATCH 2 of 3 V2] revlog: switch findmissing to use ancestor.missingancestors, and add a revs variant

[Siddharth Agarwal]

On 11/22/2012 07:57 AM, Greg Ward wrote:
> Sounds like two changes to me. See
> http://mercurial.selenic.com/wiki/OneChangePerPatch . The fact that
> you're adding an unused method smells bad.

That makes sense. I'll send out a V3 on Monday with your suggestions + 
any other feedback I get incorporated.