monkey patch in the worker

this change move the monkey patching from the aribiter to the worker so we make sure the supervision won't be altered.

fix #478
fix gevent worker
fix eventlet worker

make sure we patch the listening socket in the worker
Include subprocess in the gevent monkey patching to ensure consistent behavior between gevent 1.0b3 and 1.0rc3
fix support for current but old stable gevent release
Merge branch 'fix/478' into develop