:func:`.engine_from_config` were not being parsed correctly;
these included ``pool_threadlocal`` and the psycopg2 argument
``use_native_unicode``. fixes#3435
- add legacy_schema_aliasing config parsing for mssql
- move use_native_unicode config arg to the psycopg2 dialect
VARBINARY(max) for large text/binary types. The MSSQL dialect will
now respect this based on version detection, as well as the new
``deprecate_large_types`` flag.
fixes#3039
pyodbc will no longer specify a default "driver name", and a warning
is emitted if this is missing. The optimal driver name for SQL Server
changes frequently and is per-platform, so hostname based connections
need to specify this. DSN-based connections are preferred.
fixes#3182
In pymssql, if you terminate a long running query manually
it will give you a connection reset by peer message, but this
connection remains in the pool and will be re-used.
Mike Bayer