copy & rename can ignore removed source files
As mercurial now distinguishes deleted files from removed files,
we can skip removed source files while copying or renaming.
%%% should show a removed and b added
A b
R a
reverting...
%%% should show b unknown and a back to normal
? b
merging a
%%% should show foo-b
foo-b
%%% should show a removed and b added
A b
R a
reverting...
%%% should show b unknown and a marked modified (merged)
? b
%%% should show foo-b
foo-b