Patch in:
commit 6f425af08f02ed6c6bf676c25864ed0f0d3554ad
Author: Megh Bhatt <meghb@juniper.net>
Date:   Tue Jan 21 14:11:39 2014 -0800

    1. Allow generators to not start HTTP introspect by passing
       -1 as HTTP port in init_generator pysandesh
    2. Add UveInterVnStats, InterVnStats, virutalmachine_list to
       UveVirtualNetworkAgentTrace message in mock generator
    3. Allow user to specify number of instances per generator
       and number of virtual networks