Add [I]REGEX function
Test another opt flag
merge nathanlws: Add [I]REGEX function

Merge pull request #1223 from nathanlws/sql-layer/add-regex
https://github.com/FoundationDB/sql-layer/pull/1223
merge MMcM: Deferrable foreign key support

Merge pull request #1225 from MMcM/sql-layer/deferrable-foreign-key
https://github.com/FoundationDB/sql-layer/pull/1225
Pull out a subclass so it can be used elsewhere.
Move non-group join conditions as well when possible.
Adjust some expected results.