changed API of coros.Job: use Job.spawn_new to create a greenlet; added coros.JobGroup
changed API of coros.Job: use Job.spawn_new to create a greenlet; added coros.JobGroup

tempbottle/eventlet,lindenlab/eventlet,lindenlab/eventlet,collinstocks/eventlet,collinstocks/eventlet,tempbottle/eventlet,lindenlab/eventlet