Add core copy detection algorithm This adds findcopies, which detects merge-relevant copies between files in a pair of manifests back to the merge ancestor. While the merge code invokes the copy detection routine, it does not yet use the result.

#!/bin/sh

mkdir t
cd t
hg init
echo a > a
hg add a
hg commit -m "test" -d "1000000 0"
hg verify
hg parents
hg status
hg rollback
hg verify
hg parents
hg status