PEP8 whitespace
PyPy 2.3 compatibility fix

In PyPy 2.3 socket.socket has no _sock property which causes eventlet
failures.
https://github.com/eventlet/eventlet/pull/97
0.15 release
Bump version to 0.16.0.dev
Python 3 compat: Use correct _fileobject
Python 3 compat: Use bytes when reading/writing
Python3 compat: InstanceType/__new__; Thanks to Jakub Stasiak