merge: shortcircuit filemerge for identical files
- use filectx.cmp to compare files
- move merge messages into filemerge
- kill the redundant resolving message
- update tests
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
abort: Permission denied: test-ro-message/b/vehicle