fix Bytes submission pb on POST, due to multiple call to field.process_form_value for a same field. In the case of file, stream.read() doesn't return file's data the second time (since the cursor is at the end of the file). Fix this by having a generic process_form_value method that cache field's value in form.formvalues[field] and so _process_form_value is only called once. You should then override that later method on custom fields.

sync_schema_props_perms('state_of')
sync_schema_props_perms('transition_of')
for etype in ('State', 'BaseTransition', 'Transition', 'WorkflowTransition'):
    sync_schema_props_perms((etype, 'name', 'String'))