py2k coverage tests were failing because of this API
usage that seems to pass on Py3k but not py2k

Change-Id: Ic7ceb03c2660f411f487fce73ce5c2fa2c752031

It's better, the majority of these changes look more readable to me.
also found some docstrings that had formatting / quoting issues.

Change-Id: I582a45fde3a5648b2f36bab96bad56881321899b

Fixes: #5506
Change-Id: I718474d76e3c630a1b71e07eaa20cefb104d11de

it's not really correct that URL is mutable and doesn't do
any argument checking.   propose replacing it with an immutable
named tuple with rich copy-and-mutate methods.

At the moment this makes a hard change to the CreateEnginePlugin
docs that previously recommended url.query.pop().  I can't find
any plugins on github other than my own that are using this
feature, so see if we can just make a hard change on this one.

Fixes: #5526
Change-Id: I28a0a471d80792fa8c28f4fa573d6352966a4a79

The pg8000 dialect has been revised and modernized for the most recent
version of the pg8000 driver for PostgreSQL.  Changes to the dialect
include:

* All data types are now sent as text rather than binary.

* Using adapters, custom types can be plugged in to pg8000.

* Previously, named prepared statements were used for all statements.
  Now unnamed prepared statements are used by default, and named
  prepared statements can be used explicitly by calling the
  Connection.prepare() method, which returns a PreparedStatement
  object.

Pull request courtesy Tony Locke.

Notes by Mike: to get this all working it was needed to break
up JSONIndexType into "str" and "int" subtypes; this will be
needed for any dialect that is dependent on setinputsizes().

also includes @caselit's idea to include query params
in the dbdriver parameter.

Co-authored-by: Mike Bayer <mike_mp@zzzcomputing.com>

Closes: #5451
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/5451
Pull-request-sha: 639751ca9c7544801b9ede02e6cbe15a16c59c82

Change-Id: I2869bc52c330916773a41d11d12c297aecc8fcd8

MySQL dialect's server_version_info tuple is now all numeric.  String
tokens like "MariaDB" are no longer present so that numeric comparison
works in all cases.  The .is_mariadb flag on the dialect should be
consulted for whether or not mariadb was detected.   Additionally removed
structures meant to support extremely old MySQL versions 3.x and 4.x;
the minimum MySQL version supported is now version 5.0.2.

In addition, as the "MariaDB" name goes away from server version,
expand upon the change in I330815ebe572b6a9818377da56621397335fa702
to support the name "mariadb" throughout the dialect and test suite
when mariadb-only mode is used.    This changes the "name" field
on the MariaDB dialect to "mariadb", which then implies a change
throughout the testing requirements system as well as all the
dialect-specific DDL argument names such as "mysql_engine" is
now specified as "mariadb_engine", etc.   Make use of the
recent additions to test suite URL provisioning so that we can
force MariaDB databases to have a "mariadb-only" dialect which
allows us to test this name change fully.

Update documentation to refer to MySQL / MariaDB explicitly
as well as indicating the "mariadb_" prefix used for options.

It seems likely that MySQL and MariaDB version numbers are going to
start colliding at some point so having the "mariadb" name
be available as a totally separate dialect name should give us
some options in this regard.

Currently also includes a date related fix to a test for
the postgresql dialect that was implicitly assuming a
non-UTC timezone

Fixes: #4189
Change-Id: I00e76d00f62971e1f067bd61915fa6cc1cf64e5e

We want TOX_POSTGRESQL and similar to be the fixed variable
that is configured from CI environment.   These variables should refer
to database servers but individual drivers like asyncpg mysqlconnector
etc. should come from local tox.ini.  add a new system to generate
per-driver URLs from a simple list of hostname-based URLs delivered
from CI environment.

Change-Id: I4267b4a70742765388c7e7c4432c1da9d9adece2

Change-Id: I431e1ef41e26d490343204a75a5c097768749768

1. ensure provision.py loads dialect implementations when running
reap_dbs.py.   Reapers haven't been working since
598f2f7e557073f29563d4d567f43931fc03013f .

2. add some exclusion rules to allow the sqlite_file target to work;
add to tox.

3. add reap dbs target for SQLite, repair SQLite drop_db routine
which also wasn't doing the right thing for memory databases
etc.

4. Fix logging in provision files, as the main provision logger
is the one that's enabled by reap_dbs and maybe others, have all
the provision files use the provision logger.

Fixes: #5180
Fixes: #5168

Change-Id: Ibc1b0106394d20f5bcf847f37b09d185f26ac9b5

Removed the imports for provision.py from each dialect
and instead added a call in the central provision.py to
a new dialect level method load_provisioning().  The
provisioning registry works in the same way, so an existing
dialect that is using the provision.py system right now
by importing it as part of the package will still continue to
function.  However, to avoid pulling in the testing package when
the dialect is used in a non-testing context, the new hook may be
used.   Also removed a module-level dependency
of the testing framework on the orm package.

Revised an internal change to the test system added as a result of
:ticket:`5085` where a testing-related module per dialect would be loaded
unconditionally upon making use of that dialect, pulling in SQLAlchemy's
testing framework as well as the ORM into the module import space.   This
would only impact initial startup time and memory to a modest extent,
however it's best that these additional modules aren't reverse-dependent on
straight Core usage.

Fixes: #5180
Change-Id: I6355601da5f6f44d85a2bbc3acb5928559942b9c