Add support for bundling metrics and enable WebSocket compression. Introduces protocol.BundlePayload and MessageTypeBundle, and handles bundled messages on the server side (handleBundleMessage) by iterating items and forwarding each to metricService.HandleMetricData. On the agent side, add bundleWriter to collect outgoing MetricsPayloads, switch collectors to write into the bundle writer, and send a single bundle message when items exist. Also enable compression on the WebSocket upgrader and create a custom websocket.Dialer (with Proxy, HandshakeTimeout and EnableCompression). Minor logging/messages and import adjustments included.
yumusb
35becefe1e