:class:`.DateTime`.  As Oracle has no "datetime" type per se,
it instead has only ``DATE``, it is appropriate here that the
``DATE`` type as present in the Oracle dialect be an instance of
:class:`.DateTime`.  This issue doesn't change anything as far as
the behavior of the type, as data conversion is handled by the
DBAPI in any case, however the improved subclass layout will help
the use cases of inspecting types for cross-database compatibility.
Also removed uppercase ``DATETIME`` from the Oracle dialect as this
type isn't functional in that context.  fixes #2987

and also will fail on py3k.
- enhance exclusions so that a requirement attribute can be passed
to fails_if/skip_if.
- fix coverage docs to mention pytest.

This feature is now turned off by default.

- implement Query with_for_update()
- rework docs and tests

- move out tests, dialect specific out of compiler, compiler tests use new API,
legacy API tests in test_selecatble
- add support for adaptation of ForUpdateArg, alias support in compilers

(e.g. for a ``CAST`` or similar) would incorrectly render ``None CHAR``
or similar. [ticket:2870]

if the synonym and the table were in different remote schemas.
Patch to fix courtesy Kyle Derr. [ticket:2853]

mssql to ensure that any literal SQL expression values are
rendered directly as literals, instead of as bound parameters,
within a CREATE INDEX statement. [ticket:2742]
- don't need expression_as_ddl(); literal_binds and include_table
take care of this functionality.