tweak gevent bug workarounds

timeout is configurable, and now long (> 10 seconds)
debug message is off by default

ref: #229
Merge pull request #311 from minrk/greenbarf

tweak gevent bug workarounds

- [x] timeout is configurable, and now long (11.6 seconds, to avoid timeout coincidences)
- [x] debug message is off by default

ref: #229