This also moves all Configurator Workflows in workflow_module to portal_workflow
(workflow_module was an implementation of Workflows based on ERP5 objects and
not using DCWorkflow code).

* Workflows are now defined on on portal_workflow._chains_by_type anymore but,
  as everything else, on the Portal Type itself.
* portal_workflow can contain and work at the same time with legacy and new
  Workflows (ERP5Type/patches/DCWorkflow.py monkey-patching DCWorkflow classes
  to provide the same API).
* Existing Workflow Scripts should work as they are and the code can be updated
  later on to take advantage of the new API:
  + With legacy implementation Workflow {Scripts,Transitions,Worklists,States}
    were in a Folder ({scripts,transitions,worklists,states} attribute) but
    all of these are now in the Workflow itself and their IDs are prefixed
    (PropertySheet-style), for example `script_`. Legacy attributes are
    provided in new implementation to call the new API.
  + When calling a Workflow Script, `container` was bound to its parent, namely
    WF.scripts (Folder) and a Workflow Script could call another. Now `container`
    is bound to the WF itself and Workflow Scripts are in a Workflow directly.
    New implementation `scripts` attribute handle such use case.
  + Override portal_workflow.__getattr__ so that a Workflow Script can call
    another one without prefix.
* Worklist are Predicate: Worklist filter objects based on given criterions and
  thus it makes more sense for a Worklist to be a Predicate (albeit a Predicate
  with only Identity Criterion and nothing else).
  + Criterion Properties:
    * state_variable.
    * local_roles (SECURITY_PARAMETER_ID).
    * Any Workflow Variables with for_catalog == 1.

erp5_performance_test:testWorkflowPerformance were ran to compare DCWorkflow
and ERP5Workflow implementations and it seems to be about 4% slower with the
new implementation (legacy: 7.547, 7.593, 7.618, 7.59, 7.514 and new: 7.842,
7.723, 7.902, 7.837, 7.875).

Work done by Wenjie Zheng, Isabelle Vallet, Sebastien Robin and myself.