Add MaxReorgLength and change stake min confirmations.
Add checkpoint with genesis block.

Splitting fee between miner and DeStream extracted to function.
In consensus, sum of fees of all transactions is split, not each fee.

Reserve balance should be in Satoshis

- Update magic bytes in testnet and mainnet;
- Update genesis and fee wallets addresses;
- Update seed nodes;
- Set POS and POW reward at mainnet;
- Change app root folder to DeStreamNode.

Only worker that finds solution to POS should add output with fees.
Otherwise, race condition occurs and output with fee is added multiple
times and not in right place, causing consensus to reject block with
bad signature exception.

Sending all fees to same address will make funds on that address
unspendable - it will never be enough confirmations on top of last
transactions. Taking random address from pool will prevent this issue.

Consensus checks that fee is charged from all spent funds (not change)
and is split between miner and DeStream

Input with pointer to change output conflicts with consensus rules as
there is no underlying transaction with funds for that input. Consensus
modified to ignore that input in funds checks.

To secure that fee is charged from spending coins and not from change,
DeStream marks output with change.
It is implemented via additional empty input with PrevOut hash
uint256.Zero, that points to output with change. Input is signed, so
it's verified that user has access to address from output, and this is
change address.

Before the network is fully established, some blocks must be mined, not
stacked. Fee should be applied to transactions in mined blocks too.

Fee is calculated based on fixed rate and splits up between miner and
DeStream wallet. Fee and split rates are network parameters.
Fee check is disabled, DeStream don't have minimal or maximal fee.
Funds are sent to DeStream wallet via additional output of CoinStake
transaction.

Cointype for DeStream - 3564, 0x80000dec (DeStream Coin). Leading
symbol in address - D

Splitting initial coins to multiple addresses allows creating multiple
transactions from initial wallet in one block. Also, all funds won't be
locked awaiting confirmations, just part of them.

Processing genesis block in wallet at every wallet initialization is
unnecessary, doing it only at synchronizing from first block is enough.

From stratis PR#1634, commit df43989243138c05fb23cd549b7b71f60a336e35

Coins are emitted in genesis block. To make them spendable, they are
added to CoinView. WalletManager changed to include them in wallet's
balance.