Conflicts:
	lib/sqlalchemy/orm/mapper.py

Fixed two typos.

of mappers used in polymorphic inheritance loads is sorted on class name,
which allows the SELECT statements generated for polymorphic queries
to have deterministic rendering, which in turn helps with caching
schemes that cache on the SQL string itself.
[ticket:2779]

value is present

mapped class where the polymorphic discriminator has been assigned
to a value that is invalid for the class.   [ticket:2750]

the creation of strong references within the Session;
an object will no longer have an internal reference cycle
created if it's in the transient state or moves into the
detached state - the strong ref is created only when the
object is attached to a Session and is removed when the
object is detached.  This makes it somewhat safer for an
object to have a `__del__()` method, even though this is
not recommended, as relationships with backrefs produce
cycles too.  A warning has been added when a class with
a `__del__()` method is mapped.
[ticket:2708]

query when refreshing an inheritance-mapped class
where the superclass was mapped to a non-Table
object, like a custom join() or a select(),
running a query that assumed a hierarchy that's
mapped to individual Table-per-class.
[ticket:2697]

  subclass could insert the row for the "sub" table
  before the parent table, if the two tables had no
  ForeignKey constraints set up between them.
  Also in 0.7.11. [ticket:2689]
- fix a glitch in the assertsql.CompiledSQL fixture regarding
when a multiparam compiledSQL is used within an AllOf
- add a new utility function randomize_unitofwork() which
does the function of --reversetop