change SQL on db_* calls to {}, remove bcms::folder::get_page_folder, get_image_folder, get_file_folder out since they are bcms-ui-wizard specific, added bcms::folder::is_registered_content_type, move queries of bcms::folder::get_id_by_package_id to xql files
change SQL on the db_* calls to {}, made the api doc better. removed -content_type on bcms::revision::list_revisions. bcms::revision::set_status now throws an error