Implement configurable buffer sizes. Also addresses:
- Pass copies rather than original byte buffers to application code
- Implement user properties for sessions
- Ensure sessions are only closed once
- Make calling of onClose() consistent



git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1438229 13f79535-47bb-0310-9956-ffa450edef68