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
db_pool: customizable connection cleanup function; Thanks to Avery Fay

https://github.com/eventlet/eventlet/pull/64

Also:
- PEP8
- except Exception
- .put() must not catch SystemExit
WIP on issue https://github.com/eventlet/eventlet/issues/95