- fix the targeting of module names moved around by using custom handlers for "Bases", etc.

cherry pick of 0c19c1c66f3a115f5ce710de571552d68fac6358 from 0.9.   there's likely issues to be fixed.

provides the functionality of query.with_polymorphic()
in a standalone form.   It can be applied to any
entity within a query, including as the target
of a join in place of the "of_type()" modifier.
[ticket:2333]
- redo a large portion of the inheritance docs in terms
of declarative, new with_polymorphic() function
- upgrade examples/inheritance/polymorph, rename to "joined"

"basic relationship" examples, cleaned up the examples and added
some more explicitness.  Also renamed "treenodes" to "nodes" and
added self-referential declarative example.
- Added info/examples on how to join tables directly when querying with
joined table inheritance.
-  Starting to talk about hybrids in the main mapper docs some more.
introducoed the idea that synonyms are on their way out.
- SQL expressions as mapped attributes also gets better verbiage,
alternative approaches to them, including hybrids.
- modernized the hybrid example.
- object_session() as a standalone function wasn't documented ?!

- converted all eager to joined in examples
- fixed beaker/advanced.py to reference RelationshipCache

relationship(), to eliminate confusion over the relational
algebra term.  relation() however will remain available
in equal capacity for the foreseeable future.  [ticket:1740]

- added READMEs to all examples in each __init__.py and added to sphinx documentation
- added versioning example
- removed vertical/vertical.py, the dictlikes are more straightforward