test-merge-tools: windows fixes
- /bin/cat does not exist, expect 'cat'
- non-interactive mode is not correctly detected in pysh, force it
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
removing b
created new head
% should abort
abort: crosses branches (use 'hg merge' or 'hg update -C' to discard changes)
% should succeed
abort: crosses branches (use 'hg merge' or 'hg update -C')