Abstract the test class some more to address more conflict
types. This currently fails
test_resolve_taking_other(dir_renamed,dir_deleted) because the
conflict object doesn't record the file-id involved.

* bzrlib/tests/test_conflicts.py:
(resolve_conflict_scenarios): Renamed from
content_conflict_scenarios because we basically want to use the
same tests for various conflict types.
(TestParametrizedResolveConflicts): Add more attributes.
(TestParametrizedResolveConflicts.setUp): Create a dir for other
types of conflicts.
(TestParametrizedResolveConflicts.assertConflict): Use the
conflict type parameter instead of requiring the method parameter.
(TestParametrizedResolveConflicts.do_rename_dir,
TestParametrizedResolveConflicts.check_dir_renamed,
TestParametrizedResolveConflicts.do_delete_dir,
TestParametrizedResolveConflicts.check_dir_doesnt_exist): More helpers.