Extend tracking of isolation levels through to the transaction service, where something interesting might happen.
Centralize selection of transaction scan options for operator.
Hook those together so that SET TRANSACTION ISOLATION LEVEL selects appropriate scan options for operators.
Allow getting scan options without a transaction for tests that create cursors and only then begin before opening them.
Need a getSnapshotFuture.
Add new isolation levels for embedded JDBC using negative ints.
Make default schema in embedded JDBC more reliable.
That new overload was a bad idea.
Also check before starting iterator, for the case of multiple statements.
Add snapshot IT showing that whereas serializable conflicts, this skews.
Add read committed IT showing that "long" scans complete with expected isolation violations.
Switch to using ErrorCode, since that makes it clearer.
Allow setting transaction options in embedded connection properties.
Add DT to check long-running scans / transactions.
Pass transaction options to various kinds of scans, which actually makes things simpler.
Also test (negatively) snapshot with long-running query.
Commit transaction when switching to read-only after writing some.
Add (ignored) test of snapshot RYW.
merge MMcM: Implement new isolation levels

Merge pull request #1576 from MMcM/sql-layer/isolation-levels
https://github.com/FoundationDB/sql-layer/pull/1576