Fixed bug in new percent-sign support (e.g. :ticket:`3740`) where a bound
parameter rendered with literal_binds would fail to escape percent-signs
for relevant dialects.  In addition, ensured new table / column comment
support feature also fully makes use of literal-rendered parameters so that
this percent sign support takes place with table / column comment DDL as
well, allowing percent sign support for the mysql / psycopg2 backends that
require escaping of percent signs.

Change-Id: Ia4136a300933e9bc6a01a7b9afd5c7b9a3fee4e3
Fixes: #4054
Fixes: #4052

Fixed bug where an index reflected under Oracle with an expression like
"column DESC" would not be returned, if the table also had no primary
key, as a result of logic that attempts to filter out the
index implicitly added by Oracle onto the primary key columns.

Reworked the "filter out the primary key index" logic in oracle
get_indexes() to be clearer.

This changeset also adds an internal check to ColumnCollection
to accomodate for the case of a column being added twice,
as well as adding a private _table argument to Index such that
reflection can specify the Table explicitly.  The _table
argument can become part of public API in a later revision
or release if needed.

Change-Id: I745711e03b3e450b7f31185fc70e10d3823063fa
Fixes: #4042

Pull-request: https://github.com/zzzeek/sqlalchemy/pull/326
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/342

Fixes: #4002
Change-Id: I221fe8ba305fc455a03e3a5d15f803bf8ee2e8fb

After bump minimum supported version to 2.7 (1da9d3752160430c91534a8868ceb8c5ad1451d4), we can use new syntax.

Change-Id: Ib064c75a00562e641d132f9c57e5e69744200e05
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/347

Added support for SQL comments on :class:`.Table` and :class:`.Column`
objects, via the new :paramref:`.Table.comment` and
:paramref:`.Column.comment` arguments.   The comments are included
as part of DDL on table creation, either inline or via an appropriate
ALTER statement, and are also reflected back within table reflection,
as well as via the :class:`.Inspector`.   Supported backends currently
include MySQL, Postgresql, and Oracle.

Co-authored-by: Mike Bayer <mike_mp@zzzcomputing.com>
Fixes: #1546
Change-Id: Ib90683850805a2b4ee198e420dc294f32f15d35d

Oracle reflection now "normalizes" the name given to a foreign key
constraint, that is, returns it as all lower case for a case
insensitive name.  This was already the behavior for indexes
and primary key constraints as well as all table and column names.
This will allow Alembic autogenerate scripts to compare and render
foreign key constraint names correctly when initially specified
as case insensitive.

Change-Id: Ibb34ec6ce7cb244d1c4ae9d44ce2d37d37227e69
Fixes: #3276

Ported the fix for Oracle quoted-lowercase names to Firebird, so that
a table name that is quoted as lower case can be reflected properly
including when the table name comes from the get_table_names()
inspection function.

Also genericize the test to the test suite for denormlized name
dialects.

Fixes: #3548

Change-Id: I8ca62e8d2b359e363ccb01cfe2daa0995354a3cb

Change-Id: I2dc6961f9b692a8bb6bfb2296d159df145dec679

Regarding 0e88bcc30ed49193b91f248123f526fa30007f22, "options"
needs to be present as a key in the dictionary because Alembic
uses this as a guide to know if the backend is even capable of
reporting on foreign key options.

Change-Id: I271090f75088cfeec24315a878060f9b8a265335