"auto increment" column has been changed, such that autoincrement
is no longer implicitly enabled for a :class:`.Table` that has a
composite primary key.  In order to accommodate being able to enable
autoincrement for a composite PK member column while at the same time
maintaining SQLAlchemy's long standing behavior of enabling
implicit autoincrement for a single integer primary key, a third
state has been added to the :paramref:`.Column.autoincrement` parameter
``"auto"``, which is now the default. fixes #3216
- The MySQL dialect no longer generates an extra "KEY" directive when
generating CREATE TABLE DDL for a table using InnoDB with a
composite primary key with AUTO_INCREMENT on a column that isn't the
first column;  to overcome InnoDB's limitation here, the PRIMARY KEY
constraint is now generated with the AUTO_INCREMENT column placed
first in the list of columns.

- repair the CREATE INDEX ddl for schemas
- update provisioning to include support for setting up ATTACH DATABASE up front
for the test_schema; enable "schemas" testing for SQLite
- changelog / migration notes for new SQLite schema support
- include the "schema" as the "remote_schema" when we reflect SQLite FKs

Should return "main" and the names of attached databases.

and regexp parsing of SQL in order to form a complete picture of
constraints + their names.  fixes #3244 fixes #3261
- factor various PRAGMA work to be centralized into one call

:class:`.sqlite.TIME`,
or :class:`.sqlite.DATETIME` types, and given a ``storage_format`` that
only renders numbers, will render the types in DDL as
``DATE_CHAR``, ``TIME_CHAR``, and ``DATETIME_CHAR``, so that despite the
lack of alpha characters in the values, the column will still
deliver the "text affinity".  Normally this is not needed, as the
textual values within the default storage formats already
imply text.
fixes #3257

test both memory and file-based
- When selecting from a UNION using an attached database file,
the pysqlite driver reports column names in cursor.description
as 'dbname.tablename.colname', instead of 'tablename.colname' as
it normally does for a UNION (note that it's supposed to just be
'colname' for both, but we work around it).  The column translation
logic here has been adjusted to retrieve the rightmost token, rather
than the second token, so it works in both cases.   Workaround
courtesy Tony Roberts.
fixes #3211