add set_page_data as well

#473188: missing get_page_data when patching bare db-api request for web compatibility

benefit from the orm for clearer code

close #472361: omit password and bytes attributes in allowed mass-mailing keys by fixing default implementation for allowed_massmail_keys() in the Emailable pluggable mixin (cw.common.mixins). Added test (in entities.test though), also fix CWUserTC classes conflicts in the test module.