Add a copyResultColumnsFromLeft() for use in the AISBinder in the Union
processing to allow for nested unions and select * to function
correctly.
merge tjoneslo: Add a copyResultColumnsFromLeft() for use in the AISBinder

Merge pull request #62 from tjoneslo/sql-parser/add-set-operator-deep-copy
https://github.com/FoundationDB/sql-parser/pull/62