Patch in: e9572f3e8e78ca5ce44b7e0ec84568dea97adb8c

commit e9572f3e8e78ca5ce44b7e0ec84568dea97adb8c
Author: Megh Bhatt <meghb@juniper.net>
Date:   Mon Dec 30 16:51:38 2013 -0800

    1. Change TCP session reader task for vizd from the sandesh state
       machine task to the IO reader task so that the sandesh message
       reading and processing can happen in parallel. This reverts the
       change done as part of bug 1729 to make the session reader task
       and state machine task exclusive. The issue mentioned in bug
       1729 is handled by setting the session sandesh message receive
       callback to NULL as part of session delete/close which happens
       from the state machine task.
    2. Increase the VizSession receive buffer size to 16K from 4K
       since the Sandesh client average send is around 10K bytes.

    With the above 2 changes, on a single box setup, vizd is able to
    receive 50K flow samples at steady state with no drops on the sandesh
    client.