cvsps: add two more tiebreakers in cscmp test-convert-cvs.t has been a little flaky for a while now. Add an extra tiebreaker in cscmp so that all the cases in the test will sort reliably. Without this patch, test-convert-cvs.t failed after 346 runs. With this patch, I stopped trying to get it to fail after 615 runs. While not conclusive, that makes me pretty optimistic that this is a working fix.