SQLite allows column types that aren't technically understood in sqlite
by using 'data affinity', which is an algorithm for converting column
types in to some sort of useful type that can be stored and retrieved
from the db. Unfortunatly, this breaks reflection since we (previously)
expected a sqlite db to reflect column types that we permit in the
`ischema_names` for that dialect.

This patch changes the logic for 'unknown' column types during
reflection to instead run through SQLite's data affinity algorithm, and
assigns appropriate types from that.

It also expands the matching for column type to include column types
with spaces (strongly discouraged but allowed by sqlite) and also
completely empty column types (in which case the NullType is assigned,
which sqlite will treat as a Blob - or rather, Blob is treated as
NullType). These changes mean that SQLite will never raise an error for
an unknown type during reflection - there will always be some 'useful'
type returned, which follows the spirit of SQLite (accomodation before
sanity!).

where a more specific type is adapted to a more generic one - this
use case is needed by some third party tools such as ``sqlacodegen``.
The specific cases that needed repair within this test suite were that
of :class:`.mysql.ENUM` being downcast into a :class:`.types.Enum`,
and that of SQLite date types being cast into generic date types.
The ``adapt()`` method needed to become more specific here to counteract
the removal of a "catch all" ``**kwargs`` collection on the base
:class:`.TypeEngine` class that was removed in 0.9. [ticket:2917]

- clean up some shenanigans in reflection

arguments; [ticket:2866]
- add dialect specific kwarg functionality to ForeignKeyConstraint, ForeignKey

- be specific about version 0.9.2

to be very slow.  this now has the effect of producing "conditional" unicode
conversion for the Oracle backend, as it still returns NVARCHAR etc. as unicode
[ticket:2911]
- add new "conditional" functionality to unicode processors; the C-level
function now uses PyUnicode_Check() as a fast alternative to the isinstance()
check in Python