[jaring] lib.Jaring: get, check, and set profile id.

* cookies_get: get profile id in cookie.
* db_prepare_id: add profile id to parameter data.
* request_read:
   - filter by profile id.
   - check return value for request_update_after.
* request_delete: disallow user to delete data where profile id is 1.
* request_upload_check_err: function to set error message for uploaded file.