Merge pull request #35 from Juniper/fix

- track packets dropped in the linux specific layer
Ensure that software interrupt is triggered immediately after NAPI call on
the GRO interface when the call is initiated as a result of the agent
enabling a flow for forwarding.
Merge pull request #37 from srajag/master

Ensure that software interrupt is triggered immediately after NAPI call ...
Merge pull request #38 from Juniper/master

merge master to fix