method, and its interaction with result-row processing, now allows
the columns passed to the method to be positionally matched with the
result columns in the statement, rather than matching on name alone.
The advantage to this includes that when linking a textual SQL statement
to an ORM or Core table model, no system of labeling or de-duping of
common column names needs to occur, which also means there's no need
to worry about how label names match to ORM columns and so-forth.  In
addition, the :class:`.ResultProxy` has been further enhanced to
map column and string keys to a row with greater precision in some
cases.  fixes #3501
- reorganize the initialization of ResultMetaData for readability
and complexity; use the name "cursor_description", define the
task of "merging" cursor_description with compiled column information
as its own function, and also define "name extraction" as a separate task.
- fully change the name we use in the "ambiguous column" error to be the
actual name that was ambiguous, modify the C ext also

such as :meth:`.Query.union` now handle the case where the embedded
SELECT statements need to be parenthesized due to the fact that they
include LIMIT, OFFSET and/or ORDER BY.   These queries **do not work
on SQLite**, and will fail on that backend as they did before, but
should now work on all other backends.
fixes #2528

(hence becoming two regressions); reports that
SELECT statements would GROUP BY a label name and fail was misconstrued
that certain backends such as SQL Server should not be emitting
ORDER BY or GROUP BY on a simple label name at all; when in fact,
we had forgotten that 0.9 was already emitting ORDER BY on a simple
label name for all backends, as described in :ref:`migration_1068`,
as 1.0 had rewritten this logic as part of :ticket:`2992`.

In 1.0.2, the bug is fixed both that SQL Server, Firebird and others
will again emit ORDER BY on a simple label name when passed a
:class:`.Label` construct that is expressed in the columns clause,
and no backend will emit GROUP BY on a simple label name in this case,
as even Postgresql can't reliably do GROUP BY on a simple name
in every case.
fixes #3338, fixes #3385

assign the proper result type of Boolean to the result mapping, and
instead would leak column types from within the query into the
result map.  This issue exists in 0.9 and earlier as well, however
has less of an impact in those versions.  In 1.0, due to #918
this becomes a regression in that we now rely upon the result mapping
to be very accurate, else we can assign result-type processors to
the wrong column.   In all versions, this issue also has the effect
that a simple EXISTS will not apply the Boolean type handler, leading
to simple 1/0 values for backends without native boolean instead of
True/False.   The fix includes that an EXISTS columns argument
will be anon-labeled like other column expressions; a similar fix is
implemented for pure-boolean expressions like ``not_(True())``.
fixes #3372

agaisnt -> against
'a Alias' -> 'an Alias'

the string label placed in the order_by() or group_by() of a statement
would place higher priority on the name as found
inside the FROM clause instead of a more locally available name
inside the columns clause.
fixes #3335

for the slots-based __getattr__ thing getting hit