Add deprecated comments to legacy InvVect_* consts.
Add deprecated comments to legacy InvVect_* consts.

This makes it a little more obvious in the documentation that they are
deprecated.

runeaune/btcd,adiabat/btcd,FactomProject/btcd,btcsuitereleases/btcd,jongillham/btcd,ltcsuite/ltcd,jrick/dcrd,toddfries/btcd,wallclockbuilder/btcd,tb00/btcd,jongillham/btcd,DanielKrawisz/btcd,Stash-Crypto/btcd,Dirbaio/btcd,cjepson/btcd,jcmincke/dcrd,btcsuite/btcd,glv2/ppcd,ppcsuite/ppcd-old,Dirbaio/btcd,stevenroose/btcd,Cleawing/btcd,BitGo/prova,jrick/btcd,aakselrod/btcd,qchain/btcd,ppcsuite/ppcd,soapboxsys/ombfullnode,CryptocurrencyCabal/htcd,adiabat/btcd,FactomProject/btcd,hectorj/btcd,jimmysong/btcd,decred/dcrd,Stash-Crypto/btcd,pkothbauer/btcd,Cleawing/btcd,jcmincke/dcrd,dajohi/btcd,BitGo/prova,DanielKrawisz/btcd,jcmincke/dcrd,pkothbauer/btcd,danoctavian/btcd,runeaune/btcd,Roasbeef/btcd,danoctavian/btcd,tb00/btcd,ppcsuite/ppcd-old,soapboxsys/ombfullnode,1d4Nf6/btcd,ppcsuite/ppcd,davecgh/btcd,cjepson/btcd,aakselrod/btcd,decred/dcrd,btcsuitereleases/btcd,cqswxj2013/btcd,Dirbaio/btcd,jrick/btcd,jrick/btcd,dan-da/btcd,jimmysong/btcd,davecgh/btcd,ltcsuite/ltcd,CryptocurrencyCabal/htcd,dajohi/btcd,btcsuite/btcd,cqswxj2013/btcd,dan-da/btcd,mathiasrw/btcd,mathiasrw/btcd,hectorj/btcd,toddfries/btcd,Roasbeef/btcd,stevenroose/btcd,1d4Nf6/btcd,glv2/ppcd,wallclockbuilder/btcd,qchain/btcd,dajohi/btcd,jrick/dcrd