Add testcase for %ghost shared with a real file

Add testcase for %ghost shared with a real file

- Further parametrize conflicttest.spec to allow for different attributes
- Verify that the real file gets created without conflicts, that
  it doesn't get removed when ghost is removed and gets normally removed
  on erase.
- This is the case commit a712252392eca75443ca45c10a72873cabec7963 was
  supposed to fix (which it does but with, ahem, "slight" side-effects)
(cherry picked from commit 0485eab2c96173d1e34e4edb3570e58a693e255e)