Check custodian grants before a block is accepted
Check custodian grants before a block is accepted

The check was previously in SetBestChain because it was certain we had
all the chain there. But we already have that in AcceptBlock before the
block is written to disk (a block in the index should have all its
parents also in the index). So it's better there.

CoinGame/NuShadowNet,CoinGame/NuShadowNet,CoinGame/NuShadowNet,CoinGame/NuShadowNet,CoinGame/NuShadowNet