Allocate receive buffers in on the fly
Merge pull request #4381

806fd19 Allocate receive buffers in on the fly (Pieter Wuille)
Make CBlockIndex a subclass of CBlockHeader
Unify CBlockHeader::hashPrevBlock and CDiskBlockIndex::hashPrev
Unify GetHash() and GetBlockHash()
Remove GetBlockHeader()
CBlockIndex* CDiskBlockIndex::CreateIndex() instead of manual mapping