Decoration Based PacketIn Filter

It is noisy when packets goes into a handler of EventOFPPacketIn indiscriminately. Then, we introduce API which filters a packet. API is decorator and a filtering algorithem is pluggable.

Signed-off-by: Satoshi Kobayashi <satoshi-k@stratosphere.co.jp>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>