"auto" now so True can indicate the dialect would support this

Change _process_colparams method to remove duplicate isinstance calls
and try to speed up processing of the parameters.

"auto", doesn't matter if there's a default here

Docstring typo keysowrds => keywords

"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.

symbols with names quoted to force all-lower-case would not be
identified properly in reflection queries.  The :class:`.quoted_name`
construct is now applied to incoming symbol names that detect as
forced into all-lower-case within the "name normalize" process.
fixes #3548