This patch makes tap-as-a-service(taas) usable in networking-spp. Documents for taas are not included in this patch. The documents will be committed in another patch. Change-Id: Iab3dd1ebcf7775b0a490fbfbe6e0824c7b74742e Blueprint: taas-support
migrate from https://github.com/ntt-ns/networking-spp commit 6500ca753777a93b349d2f37881c52902576761d (tag queens-base). Change-Id: Id87d329f4b1c9798c96bdb40f1b9d706488d95cf