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.
%%% should show a removed and b added
A b
R a
reverting...
undeleting a
forgetting b
%%% should show b unknown and a back to normal
? b
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
merging a
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
%%% should show foo-b
foo-b
%%% should show a removed and b added
A b
R a
%%% revert should fail
abort: uncommitted merge - please provide a specific revision
%%% revert should be ok now
undeleting a
forgetting b
%%% should show b unknown and a marked modified (merged)
? b
%%% should show foo-b
foo-b