Merge pull request #16 from mkambol/compareTo

5 remaining test failures missed in last commit.  All were failing due t...
Merge pull request #17 from mkambol/compareTo

[PMD-895]  Added a test class to clarify join order expectations with in...
[PMD-895]  Added support for the boolean "legacy_join_order" property, which can be added to a Logical model to force join ordering to use the legacy compareTo() logic.