Unladen swallow...

Add support for DefaultValue relational API

This one required a little more work than the others to allow a variety of different objects to be used. This is the last provider-specific relational API in the current batch so I can now work on removing the old code.
Added support for unique constraints.
GitHub Issue 839: Renamed UpdatedDatabase to ApplyMigrations and GenerateUpdateDatabaseSql to ScriptMigrations.
Updates to ILogger, see aspnet/Logging#3
Adds single-level Include to relational query. Many small fixes/improvements to query framework.
Standardize reflection shim method naming
De-nest relational query components
Commands: Log