management: Making LocalControlHeader encoding independent of Interest/Data wire

Boost.Asio support multi-buffer send operation, which is enabled in this
commit for prepending (potentially different) LocalControlHeader's to
Interest/Data wire.

Change-Id: I39b979f89f196d3e47d6466fb71f6d440bce74d4
refs: #1265
management: nfdc support and link error fix

Static INVALID_FACE_ID constant was causing link error (multiple
definitions). Now it is defined just as a constant and moved to
the general-purpose NFD-related ``encoding/tlv-nfd.hpp`` header.

Change-Id: I04295fa07f809aae9a24a531e31facf09c78729f
refs: #1198