[schema] Make syntax compatible with print_function
yams seems to exec() us sometimes (instead of __import__()), and
yams.reader uses print_function nowadays.
sync_schema_props_perms('state_of')
sync_schema_props_perms('transition_of')
sync_schema_props_perms('State')
sync_schema_props_perms('BaseTransition')
sync_schema_props_perms('Transition')
sync_schema_props_perms('WorkflowTransition')