When node accepts transaction or receives block, it tries to load all
inputs to mempool. Trying to load zero-inputs to mempool leads to
corruption - valid transaction may be removed from mempool during
conflicts check. To prevent this, inputs selection algorithms modified
to ignore zero-inputs. Conflicts check ignores them too.

Light wallet feature mostly depends on wallet's source code, which is
already modified.

If fee type is "Included", fees is charged from receiver. If fee
type is "Extra", fee is charged from sender.

If fee type is "Included", fees is charged from receiver. If fee
type is "Extra", fee is charged from sender.

Transaction fee is validated before accepting transaction to mempool

Only confirmed coinstake transactions are passed to transaction builder
as available inputs.
Inputs from coinstake transactions are not grouped to avoid spending
all coins avaliable for staking.

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