EIP-0023 Oracle pool 2.0

[scalahub]

Main features in v2.0

1. Single pool address (only one type of box). This version of the pool will have only one address, the pool address.
2. Data-point boxes will be considered as inputs rather than data-inputs. These inputs will be spent, and a copy of the box with the reward will be created.
3. Reward in tokens not Ergs. The posting reward will be in the form of tokens, which can be redeemed separately.
4. Reward accumulated in data point boxes to prevent dust. We will not be creating a new box for rewarding each posting. Instead, the rewards will be accumulated in data-point boxes.
5. When creating a data-point box, the pool box is not needed as data input. Creating a data-point will be decoupled from the pool, and will not require the bool box as data-input.
6. Update mechanism as before. We will have the same update mechanism as in v1.0
7. Transferable participant tokens. Participant tokens are free to be transferred between public keys
8. Longer epoch period (1 hour or 30 blocks).
9. No separate funding box. The pool box emits only reward tokens and won't be handing out Ergs. Thus, there won't be a separate funding process required.
10. Reward mechanism separate from pool. The process of redeeming the reward tokens is not part of the protocol.

[scalahub]

https://github.com/ergoplatform/eips/blob/eip23/eip-0023.md#reward-mechanism

Document mentions "We also give a sample token exchange contract", which seems to be missing. Either add the contract or remove the sentence

[greenhat]

@scalahub Could you please merge https://github.com/ergoplatform/eips/pull/78 into this PR?