Partial work on getting this thing python3 friendly.
A lot of issues with bytes/string.encoded so far.
Main culprits are in:
cassandra/
  cluster.py
  connection.py
  decoder.py
  io/asyncorereactor.py

Some additional issues with classes not being hashable in py3 if they
implement an __eq__ method for the pool.Host class. Added __hash__ method.

Replaced print <...> with print(<...>) in several places.

Added a windoes x64 environment setting to make it build successfully in
64-bit mode with VS2010 installed.

Some places required aliasing int to long for extend it's support (long ==
int in py3).