Celery has problems when non-ASCII characters are included in log messages
(i.e. from called system commands). Therefore environment variables that
influence the locale setting are reset before running the celery worker.
This commit refactors to gnuviechadmin.base state by moving the Django
specific parts into gnuviechadmin.django that is now used by
gnuviechadmin.gvaldap and gnuviechadmin.webinterface. The script
templates gnuviechadmin/gvafile/run_celery.sh and
gnuviechadmin/gvafile/settings.sh have been added.