FROM clauses when using the :meth:`.Query.update` or
:meth:`.Query.delete` methods; instead of silently ignoring these
fields if methods like :meth:`.Query.join` or
:meth:`.Query.select_from` has been called, an error is raised.
In 0.9.10 this only emits a warning.
fixes #3349
- don't needlessly call _compile_context() and build up a
whole statement that we never need.  Construct QueryContext
as it's part of the event contract, but don't actually call upon
mapper attributes; use more direct systems of determining the
update or delete table.
- don't realy need _no_select_modifiers anymore

This is useful to be able to pass in mysql_limit=1 from using the
ORM.

names in the given dictionary of values into mapped attribute names
against the mapped class being updated.  Previously, string names
were taken in directly and passed to the core update statement without
any means to resolve against the mapped entity.  Support for synonyms
and hybrid attributes as the subject attributes of
:meth:`.Query.update` are also supported.
fixes #3228

- pep8

constructs are now importable from the "from sqlalchemy" namespace,
just like every other Core construct.
- The implicit conversion of strings to :func:`.text` constructs
when passed to most builder methods of :func:`.select` as
well as :class:`.Query` now emits a warning with just the
plain string sent.   The textual conversion still proceeds normally,
however.  The only method that accepts a string without a warning
are the "label reference" methods like order_by(), group_by();
these functions will now at compile time attempt to resolve a single
string argument to a column or label expression present in the
selectable; if none is located, the expression still renders, but
you get the warning again. The rationale here is that the implicit
conversion from string to text is more unexpected than not these days,
and it is better that the user send more direction to the Core / ORM
when passing a raw string as to what direction should be taken.
Core/ORM tutorials have been updated to go more in depth as to how text
is handled.
fixes #2992

updates, and needs to be set to `synchronize_session=False` or
`synchronize_session='fetch'`; this now raises an exception, with a
message to change the synchronize setting.  This will be only a warning
in 0.9.7.  fixes #3117

MySQL, to correctly render the SET clause among multiple columns
with the same name across tables.  This also changes the name used for
the bound parameter in the SET clause to "<tablename>_<colname>" for
the non-primary table only; as this parameter is typically specified
using the :class:`.Column` object directly this should not have an
impact on applications.   The fix takes effect for both
:meth:`.Table.update` as well as :meth:`.Query.update` in the ORM.
[ticket:2912]