Added some yaml tests
Updated tests
Don't use ANTI joins if sides can be null
Added some test cases
Commented out broken tests
Updated RulesTests
Updated comment
Added one little test case
We match postgres
Removed stale comment
Updated test expectation
merge ScottDugas: Fix results for where all nullable / not in nullable

Merge pull request #1413 from ScottDugas/sql-layer/where-all-null
https://github.com/FoundationDB/sql-layer/pull/1413