Extend evilwallet with account tooling

[daria305]

Only parts needed for proper functioning of old evil wallet functionalities are finished in this PR.

• when spamming all generated mana is for now allotted to faucet accountID, later user would be able to provide account alias of account created with accounts tool

To test the spammer make sure to update: config.json fields with data used for snapshot creation, by defualts it is setup for docker network.

"genesisOutputID",  "blockIssuerPrivateKey", "accountID"

This PR solves parts of following issues:

• spammer creates blocks on the client side and handle mana allotment: issue evil spammer allotting Mana in tx and burning Mana in blocks according to RMC #285
• create additional wallet able to create, transition accounts and save its state, so that evil spammer can use it too: issue Evil Accounts spammer #206

Solved issue parts:

• extend transaction builder in iota.go with accounts
• align configuration setup with recent node changes
• simple account spammer, we create new accounts from faucet funds, we do not handle those accounts
• account handling tools separated from evil spammer, like go run . accounts
• solution to keep the state with basic spammer, it creates wallet.dat file storing the wallet state
  - both accounts tool and evil spammer use the same accountsWallet read from wallet.dat file so we can
• make sure mana is not lost during block creation for evil spammer, all mana is allot to the faucet
• adapt to new outputID calculation principles
• fix RMC endpoint nil reference error

Work with iota.go PR: iotaledger/iota.go#569