if we already have a table; this prevents reentrant calls and
we aren't supporting columns/etc being moved around between different parents

:class:`.SynonymProperty` and :class:`.ComparableProperty`.
- The ``info`` parameter has been added as a constructor argument
to all schema constructs including :class:`.MetaData`,
:class:`.Index`, :class:`.ForeignKey`, :class:`.ForeignKeyConstraint`,
:class:`.UniqueConstraint`, :class:`.PrimaryKeyConstraint`,
:class:`.CheckConstraint`.

fixes #2963

be always be correctly propagated when one CTE referred to another
aliased CTE in a statement.
Fixes #3154

a mis-named unit test such that so-called "schema" types like
:class:`.Boolean` and :class:`.Enum` could no longer be pickled.
fixes #3144

simplify tox again now that we can exclude tests more easily

e.g. the ``func`` construct.  Previously, behavior for this method
was undefined.  The current behavior mimics that of pre-0.9.4,
which is that the function is turned into a single-column FROM
clause with the given alias name, where the column itself is
anonymously named.
fixes #3137

- add support for IDENTITY INSERT setting for INSERT with inline VALUES