e.g. values that are normally bound parameters but due to context must
be rendered as strings, typically within DDL constructs such as
CHECK constraints and indexes (note that "literal bind" values
become used by DDL as of :ticket:`2742`).  A new method
:meth:`.TypeEngine.literal_processor` serves as the base, and
:meth:`.TypeDecorator.process_literal_param` is added to allow wrapping
of a native literal rendering method. [ticket:2838]
- enhance _get_colparams so that we can send flags like literal_binds into
INSERT statements
- add support in PG for inspecting standard_conforming_strings
- add a new series of roundtrip tests based on INSERT of literal plus SELECT
for basic literal rendering in dialect suite

ideas in general:
  - pypy2.1 w/ sqlite3 is the first DBAPI we're seeing returning
    unicode in cursor.description without being py3k.  add a new on-connect
    check for this, if we get back a u"", just don't do description decoding,
    should be OK for now.
  - the set tests in test_collection were assuming the two sets would be ordered
    the same when it tested pop(), can't really assume that.
  - test_serializer gets worse and worse, pickle is just not really viable here,
    ding out pypy
  - pypy2.1b2 seems to allow cursor.lastrowid to work (or we changed something?)
  - pool._threadconns.current() is a weakref, it can be None
  - another one of those logging.handlers imports

:meth:`.Insert.from_select`.  Given a list of columns and
a selectable, renders ``INSERT INTO (table) (columns) SELECT ..``.
While this feature is highlighted as part of 0.9 it is also
backported to 0.8.3. [ticket:722]
- The :func:`.update`, :func:`.insert`, and :func:`.delete` constructs
will now interpret ORM entities as FROM clauses to be operated upon,
in the same way that select() already does.  Also in 0.8.3.

Reflection of indexes must preserve the order of columns.

Fixes issue 2767.

Fix unique constraints reflection in SQLite and PostgreSQL

Reflection of unique constraints must preserve the order of columns.