and dynamic_varible to dynamic_variable

There was bad displaying and escaping on the list.

DynamicClassGeneration_resetDynamicDocuments interaction should be apply to _setTypeWorkflow... methods: resetDynamicDocumentsOnceAtTransactionBoundary method will be run when a transaction finishes (eg. self.commit() has been called).

needed for inheritance of testWorkflowMixin class

add workflow method to get transitions list and by id
  getTransitionValueList
  getTransitionValueById

change and rename method to return a dict
create new method to return state object for a given id

changes were also applied to DC workflow, which should not be changed

rename files my_default_expr.xml to my_default_expression.xml
rename default_expr to default_expression in xml files and scripts

ERP5Workflow: add variable to avoid multiple call to function and remove successive 'if/continue' for readability

ERP5Workflow: revert more changes (some Property Sheets have been moved to erp5_workflow bt5, they are back to product/ERP5/bootstrap)