Tests for order by with nested fields (Fixes #53)

implementation not changed, tests did not turn up any problems
The point of this ticket is not to test that aliased tables are handled correctly, but to test that deeply nested projections are actually converted into deeply nested projections -- e.g. `ORDER BY foo.bar.baz.buz.quux`. These tests are all testing that table aliases work correctly, which is fine to test for but I'm less concerned about that than deeply nested projections (and that's the point of #53).