Ported from Roxen 2.2: Added functionality to enable replication of argcache entries through SiteBuilder's replication system: o Added error message to http_file_answer (ImageCache) that prints a backtrace if the draw function throws an error. o Added check for id->misc->persistent_cache_crawler in ImageCache.store(). If the flag is set a refresh (update atime) of the stored argcache id is performed. o Added column index_id to local.arguments table. o Added function ArgCache.read_index_id. o Added attribute index_id to ArgCache.create_key. o Removed incorrect argument md to ArgCache plugin function call. o Added attribute server to ArgCache.encode_id. o Added attribute index_id to ArgCache.low_store. o Added function ArgCache.write_dump. o Added function ArgCache.create_remote_key. o Added function ArgCache.read_dump. o Added function ArgCache.refresh_arg. Rev: server/base_server/roxen.pike:1.761