First cut at a gevent connection class.

It seems to kind of work. The integration tests aren't working
right; that needs to be fixed before first. A simple test of the
basic functionality seems to work, but I've not yet tested the
recovery/retry and other execptional conditions.
Remove unused set.
Clean up.
Clean-up and refactor.
Use gevent as default connection class when monkey patched.
Bring back the timeout.
Small cleanup.
Add dict support for bound statements
Better logging for dict KeyErrors
Missing period
Fix whitespace
Merge branch 'master' of github.com:datastax/python-driver into bound_dicts
Merge branch 'master' into gevent

Conflicts:
	cassandra/cluster.py
	cassandra/connection.py
De-duplicate Connection implementations
Fix failing unit test
Ignore setuptools eggs, too
Use prepared statements for benchmarks
Fix max_compaction_threshold option in metadata
Correctly clear ccm after changing C* version

Conflicts:
	tests/integration/__init__.py
Fix compaction, compression options when generating schemas