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.
Also fix EAGAIN handling of large msgs for asyncore
Remove ignored tracing_enabled param of SimpleStatement
Decode TimestampType as DateType
Lowercase KS properties
Merge pull request #86 from Mishail/lowercase_ks_options

Lowercase KS properties
Merge pull request #84 from Mishail/PYTHON-52-TimesrampType

Decode TimestampType as DateType
Add docs for setting the CL on prepared statements
Quote uppercase names in CREATE statements

Done for PYTHON-51
Update changelog
Also quote column names when needed in CREATE stmts

Done for PYTHON-51
Handle latest table options in CREATE statements

For PYTHON-51
Ignore setuptools tarball
Use TypeError for bad prepared stmt param types