Major refactoring of application architecture towards better config
handling and modularization. READ FULL MESSAGE.

I took care not to break server setups with this commit.
However the next one IS GOING to break current installations.
In order to prepare for this, please update your celery
deamonizing script. Instead of using celeryd to daemonize
you must use the "manage.py celeryworker" command for daemonizing.
An supervisord config example is provided in
init/supervisor.conf.exmaple. To deamonize supervisor,
using a simple upstart script is recommended (also provided in init/).