workflows: overhaul update
- Adds more documentation.
- Fixes some sphinx errors in documentation.
- Changes imports to relives one when possible.
- Adds a new way to handle errors, to allow easy reading.
- Removes obfuscations of exceptions.
- Clarifies exceptions.
- Updates the way exception unicodes are handling.
- Fixes the behavior of stop_on_error.
- Adds Python 3 compatibility where possible.
- Adds a method to clean extra_data in a Workflow Engine object.
- Fixes problems with Python 2.6 loggers.
- Adds reliable way to handle types for BibWorkflowObject.
- Adds a method to get widget message easily.
- Adds an abstraction method for jsonalchemy conversion in workflow tasks.
- Adds more tests.
- Adds start test procedure.
- Fixes bad sorting instructions in Holding Pen.
- Improves the way of restarting workflows.
- Simplifies celery worker.
- Reorganizes tree of the module.
- Tasks cleaning and optimizations.
Signed-off-by: Guillaume Lastecoueres <guillaume.lastecoueres@cern.ch>
Reviewed-by: Jan Aage Lavik <jan.age.lavik@cern.ch>