Includes removal of adapt_like_to_iterable() as well
as _set_iterable(), uses __slots__ for collectionadapter,
does much less duck typing of collections.

- prop.compare() isn't needed; replace with prop._with_parent()
for relationships
- update docs in orm/interfaces

sqlalchemy/orm, sqlalchemy/event, sqlalchemy/testing

to get all flake8 passing

of :ticket:`3060` from verision 0.9.5.  A self-referential relationship
with lazy='dynamic' would raise a TypeError within a flush operation.
fixes #3099

didn't match.  use straight memoized_props here for now, add a perf test to check it

- The system of loader options has been entirely rearchitected to build
upon a much more comprehensive base, the :class:`.Load` object.  This
base allows any common loader option like :func:`.joinedload`,
:func:`.defer`, etc. to be used in a "chained" style for the purpose
of specifying options down a path, such as ``joinedload("foo").subqueryload("bar")``.
The new system supersedes the usage of dot-separated path names,
multiple attributes within options, and the usage of ``_all()`` options.
-  Added a new load option :func:`.orm.load_only`.  This allows a series
of column names to be specified as loading "only" those attributes,
deferring the rest.

- rework the event system so that event modules load after their
targets, dependencies are reversed
- create an improved strategy lookup system for the ORM
- rework the ORM to have very few import cycles
- move out "importlater" to just util.dependency
- other tricks to cross-populate modules in as clear a way as possible