Made test active again.
Added default value for configuration parameter "stickyReconnect".
Better formatting of transport negotiation error messages.
COMETD-503 - JavaScript WebSocket transport does not honour maxNetworkDelay with broken connections.

Backported the CometD 3 transport, and made some improvements.
The issue is fixed by always failing the outstanding messages when they time out,
without waiting an onclose event that may never arrive if the server is down.
Updated Spring and plugin versions.
Merged branch '2.8.x' into 'master'.