- [feature] SQL Server dialect can be given

- [feature] SQL Server dialect can be given
database-qualified schema names,
i.e. "schema='mydatabase.dbo'"; reflection
operations will detect this, split the schema
among the "." to get the owner separately,
and emit a "USE mydatabase" statement before
reflecting targets within the "dbo" owner;
the existing database returned from
DB_NAME() is then restored.