BIP0144+wire: introduce new segregated witness inventory types
BIP0144+wire: introduce new segregated witness inventory types

This commit adds the new inventory types for segwit which are used by
the responder to explicitly request that transactions/blocks sent for a
particular inv hash should include all witness data.

Roasbeef/btcd,tb00/btcd,aakselrod/btcd,dajohi/btcd,tb00/btcd,davecgh/btcd,aakselrod/btcd,ppcsuite/ppcd,ltcsuite/ltcd,Stash-Crypto/btcd,Stash-Crypto/btcd,ppcsuite/ppcd,davecgh/btcd,wallclockbuilder/btcd,dajohi/btcd,ltcsuite/ltcd,dajohi/btcd,btcsuite/btcd,Roasbeef/btcd,wallclockbuilder/btcd,btcsuite/btcd