- pg8000 + postgresql dialects now check for float/numeric return

- pg8000 + postgresql dialects now check for float/numeric return
types to more intelligently determine float() vs. Decimal(),
[ticket:1567]
- since result processing is a hot issue of late, the DBAPI type
returned from cursor.description is certainly useful in cases like
these to determine an efficient result processor.   There's likely
other result processors that can make use of it.  But, backwards
incompat change to result_processor().  Happy major version number..