WorkflowTool.py: add workflow_script reference in conversion codes; add a chains_by_type repair script related function.

WorkflowTool.py: repair the Expression of the converted workflow variable; finish the methods to modify chain_by_type. Now the reassignment of the converted workflows works

ERP5WorkflowTool.py: add bootstrap function to migrate the workflow tool conditionally-autoomatically.

ERP5WorkflowTool.py: some compatibility modifications, and universal method which returns a list of both DC and ERP5 workflow values.

ERP5WorkflowTool.py: modification according to naming conversion; temporary workflow now generated with reference also.

ERP5WorkflowTool.py: chang the inherance parent class order, reload the original  dtml, reload the original getWorkflowIds, reload the original all_meta_types.

This is still a work in progress