moved the class with tasks responsibilities to the tasks module
broken half implementation of queues / jobs / tasks
introduce QueueSet and a PriorityQueueSet allowing to priorities queues.
add a task decorator to add a delay function on functions
Fix the iteration over PriorityQueueSet which was not correct
started the JobsStorage model
storage of jobs
reorganize modules
use tasks / jobs in implementation
add a view for the jobs
remove _rec_name on jobs.storage
remove useless files
rename function and comment
Rationalized queues / jobs. Crawling in the mud with threads and cursors (Unable to use a closed cursor)
Thread should be a deamon to stop with the main thread
add a tricky comment
workers threads are now running fine
Replace the inheritance of the jobs storage by composition

Avoid to have a session inside of a job because the state of a session
is too volatile. it can be closed, or we want to use different session
for different action (for example, the job is created with one session
and fetched from another).
The queue keep a job which has no relation to database.
Update states and dates.

Simplified Jobs
start to add job exceptions