scalar values, for comparisons to None to also take into account
the association record itself being non-present, in addition to the
existing test for the scalar endpoint on the association record
being NULL.  Previously, comparing ``Cls.scalar == None`` would return
records for which ``Cls.associated`` were present and
``Cls.associated.scalar`` is None, but not rows for which
``Cls.associated`` is non-present.  More significantly, the
inverse operation ``Cls.scalar != None`` *would* return ``Cls``
rows for which ``Cls.associated`` was non-present.

Additionally, added a special use case where you
can call ``Cls.scalar.has()`` with no arguments,
when ``Cls.scalar`` is a column-based value - this returns whether or
not ``Cls.associated`` has any rows present, regardless of whether
or not ``Cls.associated.scalar`` is NULL or not.
[ticket:2751]

when ``clear()`` was called.
[ticket:2730]

is all related to http://bugs.python.org/issue998998

- went through examples/ and cleaned out excess list() calls

that the "id" passed from the pickler is turned into a string
to prevent against bytes being parsed on Py3K, as well as that
``relationship()`` and ``orm.join()`` constructs are now properly
serialized. [ticket:2698] and some other observed issues.