IRB Changes

Change-Id: I807896addc7a59620db8a3e49493ce2ea5e8de84
calculating MplsoUDP source port as part of flow setting and using using this for encapsulating the packe. https://bugs.launchpad.net/juniperopenstack/+bug/1369846

Change-Id: Iea16bb1bcbe572784863d403a21ae7ecc0994adf
Fixing the compilation issue on centos causeed by review request 2843.

Change-Id: I0ab2d0f8fd881449fa2ddfb6bc6effaed6d7d1f5
Defining jhash for user vrouter

Change-Id: Ibb7548f3597d3fc9e00a53ea3fe78b4eb3c6a1ef