Remove legacy stake reward calculation code.
This commit is similar to this one.
https://github.com/novacoin-project/novacoin/commit/8118d1168e4e3f87f8d19c58ec3cce36eccdb92b
- [DH] Novacoin/CBlock.cs
- [DH] Novacoin/CBlockStore.cs
- [DH] Novacoin/CTransaction.cs
- [DH] Novacoin/NetInfo.cs