abort when using 'update -m' and this is not a merge
add more testcases for updating with local changes
%%% 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