define log before import settings in celery_app

otherwise nothing works if settings.py isn't defined
Merge pull request #197 from mistio/fix_celery_log_order

define log before import settings in celery_app
Reload user session in socketio disconnection

in order to avoid saving a stale or deleted session
Reload session in socketio only if multiuser
Merge pull request #198 from mistio/beaker_socketio

Beaker socketio
Merge branch 'staging' into progress_bar