Be more careful about binding to subquery columns

it should be a column source, from the table we're looking for
merge ScottDugas: Be more careful about binding to subquery columns

Merge pull request #1419 from ScottDugas/sql-layer/constant-cast-as-column
https://github.com/FoundationDB/sql-layer/pull/1419
New test with aliased column
Use the column label for rest labels
When fixing group indices from an alter, don't need any non-grouping foreign keys.
Added another test
merge ScottDugas: Rest respects the alias provided in the sql statement

Merge pull request #1420 from ScottDugas/sql-layer/rest-alias
https://github.com/FoundationDB/sql-layer/pull/1420
merge MMcM: When rebuilding group indexes from alter, don't include foreign keys

Merge pull request #1421 from MMcM/sql-layer/add-fk-with-gi
https://github.com/FoundationDB/sql-layer/pull/1421