into(sql, *) with better datetime support

changes and tests to support into(sql, *) where the source is
a pd.DataFrame, numpy array or dynd array, bcolz.ctable, or csv

If the source has a datetime with a timezone, make use of
sqlalchemy DateTime with timezone support

This also helps with operations of the form into(*, sql) where
the sql table has datetimes with time zone
Actually I agree with you about making sure that typical cases work. I'm reminded of the CS adage: "make the common case fast." A corollary might be: "make the common case work." I will separate out into cases where typical datetime specification will work.